PSYCHOLOGY 


PSYCHOLOGY 


BY 

BURTIS   BURR   BREESE 

PROFESSOR   OF   PSYCHOLOGY   IN   THE   UNIVERSITY    OF    CINCINNATI 


ILLUSTRATED 


COPYRIGHT,  1917,  BY 
CHARLES  SCRIBNER'S  SONS 


PREFACE 

THE  present  text  aims  to  give  a  comprehensive  view  of 
the  facts,  principles,  and  theories  of  human  psychology. 
Accordingly,  the  student  will  find  that  it  represents  the 
various  points  of  view  of  modern  psychology — the  analytic 
and  the  descriptive,  the  structural  and  the  functional,  the 
genetic  and  the  physiological.  At  the  same  time  the  em- 
pirical results  of  experimental  psychology  are  used  as  far  as 
possible.  Thus  at  the  beginning  the  student  is  given  a  broader 
foundation  for  the  understanding  of  mental  life  than  could 
be~  given  by  a  more  limited  point  of  view. 

From  the  very  outset  an  attempt  has  been  made  to  dif- 
ferentiate the  metaphysical  and  the  empirical  tendencies  in 
psychology.  It  is  important  that  the  student  should  know 
when  he  is  indulging  in  naive  metaphysical  speculation,  and 
when  he  is  dealing  with  the  results  of  scientific  observation 
or  the  theories  based  upon  such  observation. 

While  I  am  in  sympathy  with  the  present  attempt  now 
being  made  in  some  quarters  to  emphasize  the  objective  and 
quantitative  aspects  of  consciousness,  nevertheless  I  confess 
the  belief  that  the  qualitative  aspect  is  still  worthy  of  psycho- 
logical consideration,  and  that,  in  order  to  get  at  this  qualita- 
tive aspect,  the  method  of  introspection  is  still  a  valid  method 
of  psychological  procedure. 

I  am  very  much  indebted  to  Mr.  Schachne  Isaacs,  In- 
structor in  Psychology,  University  of  Cincinnati,  for  prepar- 
ing the  index,  for  reading  the  manuscript  and  proofs,  and 
for  many  helpful  suggestions  in  the  preparation  of  the  text. 

Acknowledgments  are  due  for  the  use  of  illustrations 
taken  from  the  following  text-books:  Villiger's  "Brain  and 
Spinal  Cord,"  J.  B.  Lippincott  Co.;  Quain's  "Elements 


\1  PREFACE 

of  Anatomy,"  Longmans,  Green  and  Co.;  Angell's  "Psychol- 
ogy," Henry  Holt  and  Company;  Howell's  "Text-Book  of 
Physiology,"  W.  B.  Saunders  and  Company;  Pillsbury's 
"Essentials  of  Psychology"  and  Titchener's  "Text-Book  of 
Psychology,"  The  Macmillan  Company;  Thorndike's  "El- 
ements of  Psychology";  Ladd  and  Woodworth's  "Physio- 
logical Psychology"  and  Judd's  "Psychology,"  Charles  Scrib- 
ner's  Sons. 

B.  B.  B. 

University  of  Cincinnati, 
June,  1917. 


CONTENTS 


I.    INTRODUCTORY i 

Divisions  of  Psychology.  The  Procedure  of  Psychology. 
Consciousness.  Subject-Object  Nature  of  Consciousness. 
Soul.  Mind.  Self. 

II.    THE  NERVOUS  SYSTEM 21 

Consciousness  and  the  Nervous  System.  The  Gross  Struc- 
ture of  the  Brain.  The  Autonomic  Nervous  System.  Nerve- 
Cells.  Nature  of  the  Nervous  Impulse.  Kinds  of  Neurones. 
White  and  Gray  Matter.  The  Fibre  Connections  of  the 
Brain.  Localization  of  Function. 

III.  ATTENTION .     .     .       53 

Forms  of  Attention.  Neural  Basis  of  Attention.  Shifting  of 
Attention.  Range  or  Span  of  Attention.  Effect  of  Atten-  ,,,. 

tion.  Motor  Accompaniments  of  Attention.  Feeling  of 
Effort  in  Attention.  Interest  and  Attention. 

IV.  SENSATION    .     .     .     .     .     .     .     .  .  .     .     .     .  •    87 

Sensation  as  an  Element  of  Consciousness.  Pure  Sensations. 
Physiological  Basis  of  Sensation.  The  Nature  of  the  Nerve- 
Impulse.  Evolution  of  Sense-Organs.  The  Stimuli.  After- 
Effects  of  Stimulus.  Sensory  Adaptation.  Attributes  of 
Sensation.  Quality.  Intensity.  Extensity.  Duration. 
Other  Attributes.  Kinds  of  Sensations. 

V.    ORGANIC,  KIN^STHETIC,  AND  CUTANEOUS  SENSA- 
TIONS       .     .     ,     .     no 

Organic  Sensations.  Kinaesthetic  Sensations:  Muscle,  Ten- 
don, and  Joint  Sensations;  Sensations  from  Vestibule  and- 
Semicircular  Canals.  Cutaneous  Sensations:  the  End- 
Organs;  the  Brain  Centres;  Pressure-Sensations;  Pain- 
Sensation;  Sensations  of  Cold  and  Warmth. 


vill  CONTENTS 

CHAPTER  PAGE 

VI.  OLFACTORY  AND  GUSTATORY  SENSATIONS  .  .  .  130 

Olfactory  Sensations:  End-Organ;  the  Stimulus;  Classifica- 
tion. Gustatory  Sensations:  End-Organ;  Gustatory  Nerves 
and  Brain  Centres;  Stimulus;  Classification  of  Gustatory 
Sensations;  Retardation;  Mixtures,  Contrasts,  Adaptation; 
Threshold;  Complexes. 

VII.    AUDITORY  SENSATIONS 144 

End-Organ.  Brain  Centres.  The  Stimulus.  Noises.  Tones. 
Compound  Tones.  Timbre.  Beats.  Combination  Tones. 
Intensity.  Extensity.  Musical  Tones,  Consonance,  and 
Dissonance. 

VIII.    VISUAL  SENSATIONS .     166 

The  Retina.  The  Optic  Nerve  and  Optic  Centres.  Stimulus. 
Kinds  of  Visual  Sensations.  Brightness  of  Colors.  Purkinje 
Phenomenon.  Saturation.  Complementary  Colors.  The 
Color  Pyramid.  Color  Mixtures.  Light  and  Color  Adapta- 
tion. Successive  Contrasts.  Simultaneous  Contrasts.  Color 
Zones  of  the  Retina.  Color-Blindness.  Color  Theories. 
The  Young-Helmholtz  Theory.  Bering  Theory.  Ladd- 
Franklin  Theory. 

IX.     PERCEPTION 197 

Perception  of  Objects.  Complication.  Recognition.  Mean-, 
ing.  Illusions.  Hallucinations.  Perception  of  Space:  De- 
velopment of  Space  Perception;  Third  Dimension;  Space 
Errors  and  Illusions;  Localization  and  Projection  of  Audi- 
tory Sensations.  Perception  of  Time :  Elements  of  Time  Per- 
ception; the  Psychical  Present;  Sensory  Material  of  Time 
Perceptions;  the  Psychical  Present  and  the  Logical  Present; 
the  Past  and  the  Future;  the  Measure  of  Time. 

X.    MEMORY      .     .     .     .     ..•-.. 238 

The  Image.  Definition  of  Memory.  Organic  Memory.  In- 
dividual Differences  in  Memory.  The  Training  of  the  Mem- 
ory. Methods  of  Memorizing.  Forgetting.  Defects  of 
Memory.  Function  of  Memory. 

XI.     IMAGINATION     .     .    ', '    „ .     .     260 

Memory  and  Imagination.  Kinds  of  Imagination.  Repro- 
ductive Imagination.  Productive  Imagination.  Types  of 
Imagination.  Visual  Type.  Auditory  Type.  Motor  Type. 


CONTENTS  IX 


Mixed  Types.  Methods  of  Determining  the  Types  of  Im- 
agination. Imagery  in  Synsesthesia.  Concrete  and  Symbolic 
Imagination.  Image  and  Idea.  Training  of  Imagination. 
Imagination  as  a  Means  of  Supplementing  the  Present. 
Imagination  and  Behavior. 

XII.    ASSOCIATION 277 

Formation  of  Associations.  Motor  Connections.  Mental 
Connections.  Associative  Recall.  The  Laws  of  Associa- 
tion. Contiguity.  Similarity.  Partial  and  Total  Recall. 
Falsification  of  Association.  Association  Tests.  Physio- 
logical Basis  of  Association. 

XIII.  CONCEPTION 299 

Thinking.  The  Concept.  The  Formation  of  the  Concept. 
The  Psychological  and  the  Scientific  Concepts.  The  Gen- 
eral and  the  Individual  Concept.  The  Analysis  of  the  Con- 
cept. The  Image.  Consciousness  of  Meaning.  The  Inten- 
sion and  Extension  of  Concepts.  The  Genesis  and  Develop- 
ment of  the  Concept.  Language.  Origin  of  Language. 
Thought  and  Language. 

XIV.  JUDGMENT 321 

Judgment  and  Perception.  The  Nature  of  Judgment.  Judg- 
ment as  Apperception.  Judgment  as  Belief.  Judgment  as 
the  Ascription  of  Meaning.  Judgment  as  Comparison. 
Judgment  as  Evaluation.  Kinds  of  Judgments.  Analysis 
and  Synthesis.  Judgment  and  Concept.  Judgment  as  the 
Fundamental  Cognitive  Activity. 

XV.     REASONING  .     . .     338 

Inference.  Inference  and  Perception.  Inference  and  Judg- 
ment. Inference  and  Concept.  The  Nature  of  Reflective 
Thought,  or  Reasoning.  The  Steps  in  Thinking.  Kinds 
of  Reasoning.  Reasoning  and  the  Syllogism.  Imageless 
Thought.  The  Neural  Basis  of  Reason. 

XVI.    AFFECTION  AND  FEELING       .          356 

Affection.  The  Nature  of  Affection.  Kinds  of  Affection. 
Attributes  of  Affection.  Adaptation.  Affection  and  Sensa- 
tion. Pain  and  Affection.  Affection  and  Perception.  Af- 
fection and  the  Ideational  Processes.  Affection  and  Bodily 
Expressions.  Neural  Basis  of  Affection.  The  Significance 


CONTENTS 


and  Function  of  Affection.  Feeling.  Classification  of 
Feelings.  Mood.  Temperament.  Emotions.  Sentiments. 
Passion. 

XVII.    EMOTIONS 377 

James-Lange  Theory  of  Emotions.  The  Instinctive  Reac- 
tions and  Emotions.  Conditions  Which  Give  Rise  to  Emo- 
tions. Significance  of  Emotions.  Classification  of  the  Emo- 
tions. Emotions  and  Memory. 

XVIII.    CONSCIOUSNESS  AND  BEHAVIOR 397 

Volitional  Action.  Genesis  of  Motor  Activity.  The  Connec- 
tion between  Conscious  States  and  Action.  The  Law  of 
Dynamogenesis.  Control.  Effect  of  Motor  Activity  upon 
Consciousness. 

XIX.    WILL 419 

Conation.  Will.  Will  as  Self-Determination.  Will  and 
Knowledge.  Will  and  Character.  Freedom  of  the  Will. 

XX.    THE  SELF 432 

The  Unity,  Continuity,  and  Identity  of  Personal  Conscious- 
ness. The  Subject  Self,  or  Ego.  The  Empirical  Self.  Origin 
and  Growth  of  the  Self.  Contents  of  the  Self.  Conscious- 
ness of  the  Self.  Self  and  Sensation.  Self  and  Perception. 
Self  and  Attention.  Self  and  Interest.  Self  and  Feeling. 
Self  and  Will.  Sleep  and  the  Self.  Dreams  and  the  Self. 
Disturbances  of  the  Self.  Mental  or  Psychic  Blindness. 
Automatic  Writing.  Somnambulism.  Hypnosis.  Double 
Personality.  Insanity. 

BIBLIOGRAPHY  .     .     ....     .     .     .     .     .     463 

INDEX 471 


PSYCHOLOGY 


PSYCHOLOGY 

CHAPTER  I 
INTRODUCTORY 

Psychology  is  that  study  whose  task  it  is  to  point  out 
and  organize  the  observable  facts  of  conscious  life,  and  to 
formulate  the  theories,  or  hypotheses,  necessary  to  explain 
these  facts.  In  this  study  it  is  important  that  the  student 
should  distinguish  clearly  between  fact  and  hypothesis — be- 
tween what  is  obtained  through  scientific  observation  and 
what  is  logically  constructed  through  speculation.  Psychol- 
ogy was  in  its  earliest  stages  a  branch  of  philosophy,  and  was 
more  inclined  to  speculate  about  the  nature  of  consciousness 
than  to  observe  and  systematize  the  facts  connected  with  it. 
This  is  illustrated  in  the  attempts  to  explain  consciousness  in 
terms  of  the  soul,  a  metaphysical  being  beyond  actual  obser- 
vation. Modern  psychology  concerns  itself  more  with  the 
facts  and  less  with  the  ultimate  nature  of  consciousness. 

If  we  consider  all  the  facts  which  come  from  actual  ob- 
servation we  may  put  them  into  three  groups: 

1.  Facts  about  matter. 

2.  Facts  about  life. 

3.  Facts  about  consciousness. 

The  first  group  forms  the  subject-matter  of  the  material  sci- 
ences; the  second  group  forms  the  subject-matter  of  the  bio- 
logical sciences;  and  the  third  group  forms  the  subject-matter 
of  psychology. 

Divisions  of  Psychology. — There  are  a  number  of  special 
forms  of  psychology  determined  by  the  fields  of  mental  life 


2  PSYCHOLOGY 

from  which  the  psychologist  draws  his  material,  and  by  the 
methods  and  points  of  view  he  employs  in  his  study.  With 
respect  to  the  fields  of  consciousness  we  have : 

1 .  Adult  human  psychology. 

2.  Child  psychology. 

3.  Social  psychology. 

4.  Abnormal  psychology. 

5.  Animal  psychology. 

With  respect  to  methods  and  special  points  of  view  we 
have: 

1 .  Descriptive  psychology. 

2.  Experimental  psychology. 

3.  Genetic  psychology. 

4.  Functional  psychology. 

5.  Physiological  psychology. 

6.  Psychophysics. 

•  '7.  Comparative  psychology. 

Adult  Human  Psychology  considers  the  consciousness  found 
in  the  adult  human  being.  It  points  out  -the  common  quali- 
ties, processes,  and  modes  of  activity  found  in  human  beings 
generally.  Since  individuals  differ  from  each  other  in  men- 
tal characteristics,  a  study  of  these  differences  is  also  impor- 
tant. This  study  has  been  termed  individual  psychology. 

Child  Psychology  deals  with  the  conscious  states  of  the 
child.  It  takes  account  of  the  stages  of  mental  development 
through  which  the  child  passes.  Since  the  genesis  of  con- 
sciousness is  important  here,  child  psychology  is  a  part  of 
genetic  psychology;  and  since  a  large  part  of  the  child's  life 
is  spent  in  school  under  a  formal  educational  system,  child 
psychology  and  genetic  psychology  often  take  the  form  of 
educational  psychology. 

Social  Psychology  has  to  do  with  conscious  experiences 
which  are  made  possible  by  the  presence  of  an  individual 
mind  in  a  group  of  other  minds.  Such  experiences  are  due  to 
what  has  been  termed  social  consciousness.  Out  of  it  spring 
language,  laws  and  customs,  myths  and  religion — all  of  which 


INTRODUCTORY  3 

are  dependent  upon  the  existence  of  a  community  of  individ- 
uals. The  use  of  the  terms  "social  consciousness"  and  "col- 
lective mind"  must  not  be  understood  to  indicate  the  assump- 
tion of  the  existence  of  another  kind  of  consciousness  other 
than  that  found  in  individuals.  These  terms  refer  only  to 
the  conscious  states  in  individuals  which  are  due  to  a  com- 
munity of  minds.  Communities  of  people  have  the  same 
language,  customs  and  fashions,  religion  and  mythology. 
The  conscious  experiences  back  of  these  institutions  we  as- 
sume to  be  the  same  in  all  individuals.  Since  much  of  our 
mental  life  is  social,  social  psychology  overlaps  normal  adult 
psychology  and  draws  its  material  from  it.  A  subdivision  of 
social  psychology,  variously  named  as  race  psychology,  ethnic 
psychology,  or  folk  psychology,  is  interested  in  the  mental 
characteristics  of  different  races  or  peoples.  It  may  include 
the  comparison  of  the  mental  traits  found  in  different  peoples. 
We  may  compare  the  Japanese,  on  the  one  hand,  with  the 
Russians  on  the  other;  or  the  primitive  races,  like  the  Ameri- 
can Indians  or  Malays,  with  the  more  civilized  races.  A  still 
further  subdivision  might  take  up  the  study  of  classes,  pro- 
fessions, and  occupations. 

Abnormal  Psychology  deals  with  abnormal  mental  states, 
such  as  hypnotism,  double  or  multiple  personality,  fixed 
ideas,  hysterias,  mania,  melancholia,  dementia,  paranoia, 
idiocy.  Here  also  should  be  included  the  study  of  deficient 
and  exceptional  minds — the  weak-minded  and  the  genius. 
The  criminal  mind  belongs  in  this  list,  because  most  criminals 
are  abnormal. 

Animal  Psychology  takes  as  its  subject-matter  the  mental 
states  of  animals.  The  absence  of  language  in  animals  limits 
the  possibilities  of  studying  the  consciousness  which  we  know 
exists  there.  Man  can  describe  his  experience  in  language, 
but  animals  cannot.  However,  the  behavior  of  the  animal 
is  a  clew  to  the  kinds  of  consciousness  it  has.  We  may 
therefore  study  its  behavior  and  so,  indirectly,  its  conscious- 
ness. Since  we  may  proceed  from  the  lowest  animal  forms 


4  PSYCHOLOGY 

to  the  highest,  animal  psychology  may  be  genetic  in  its  point 
of  view. 

Descriptive  Psychology  is  really  a  method  of  studying  con- 
sciousness. It  analyzes,  describes,  and  classifies  conscious 
experiences. 

Experimental  Psychology  is  laboratory  psychology.  Lab- 
oratory methods  and  physical  apparatus  are  used  as  means 
of  controlling  and  studying  mental  states.  Of  course,  the 
psychologist  cannot  measure  or  weigh  the  conscious  states  of 
his  subjects.  He  cannot  even  observe  them  directly.  He 
may,  however,  measure  the  time  during  which  a  conscious 
state  exists.  He  may  measure  or  weigh  the  physical  stimuli 
and  correlate  the  results  with  the  intensities  of  the  conscious 
experiences.  He  may  also  note  the  physiological  changes 
which  take  place  in  the  body  while  the  conscious  states  are 
going  on.  For  all  this  he  uses  instruments  of  precision,  but 
nowhere  in  his  laboratory  has  he  an  instrument  that  will 
measure  a  mental  state  itself.  A  large  part  of  this  study  de- 
pends upon  the  introspective  report  given  by  the  subject. 

Genetic  Psychology  considers  the  successive  stages  of  men- 
tal growth  and  the  evolution  in  the  individual  and  in  the 
race.  We  may  use  a  pair  of  terms  that  are  common  to  biol- 
ogy and  psychology  to  designate  the  two  lines  of  development 
—phylogenesis,  or  racial  development,  and  ontogenesis,  or  indi- 
vidual development.  These  terms  really  refer  to  the  growth 
and  development  of  organisms  as  a  whole — both  mind  and 
body.  Mental  development  in  phylogenesis  includes  all  the 
stages  of  conscious  life  which  appear  in  the  evolution  of  ani- 
mal forms  from  the  lowest  to  the  highest.  These  stages  of 
development  may  be  considered  either  as  a  series  now  exist- 
ing, or  as  a  series  constituting  the  successive  stages  of  evolu- 
tion from  the  earliest  time  to  the  present.  Mental  develop- 
ment in  ontogenesis  includes  the  stages  of  development  which 
take  place  in  an  individual  from  birth  to  death.  The  biolo- 
gist finds  a  relation  between  ontogenesis  and  phylogenesis 
which  he  states  as  the  principle  of  recapitulation.  According 


INTRODUCTORY  5 

to  this  principle,  the  individual  in  embryo  passes  through  the 
same  stages  of  development  that  the  race  has  passed  through. 
Thus,  biological  recapitulation  suggests  a  problem  for  genetic 
psychology:  Does  the  child  in  his  mental  development  pass 
through  the  stages  of  mental  development  that  the  race  has 
passed  through  ? r  The  chief  problem  of  genetic  psychology, 
however,  is  that  of  making  out  the  stages  of  mental  develop- 
ment of  the  individual. 

Functional  Psychology  looks  upon  consciousness  as  a 
process.  Formerly  the  mind  was  supposed  to  possess  the 
functions  of  knowing  and  willing.  Later  a  third  function, 
that  of  feeling,  was  added.  Knowing,  feeling,  and  willing  are, 
from  the  point  of  view  of  functional  psychology,  the  functions 
of  the  mind.  A  more  recent  functional  point  of  view  asserts 
the  presence  in  the  mind  of  a  purposive  factor  which  deter- 
mines the  direction  and  nature  of  conscious  processes.  While 
external  conditions  (stimuli)  do  this  to  a  certain  extent,  it  is 
claimed  that  these  factors  are  not  sufficient  to  explain  con- 
scious activity  adequately.  A  conscious  agency,  therefore,  is 
assumed  to  account  for  the  character  of  our  conscious  states. 

Physiological  Psychology  considers  consciousness  as  either 
the  direct  outcome  or  the  correlate  of  brain  activity.  Physio- 
logical psychology  does  not,  however,  necessarily  commit 
itself  to  a  materialistic  philosophy.  For  consciousness  may 
be  non-material  or  spiritual  in  its  nature  and  yet  be  depen- 
dent upon  the  brain  for  an  opportunity  to  manifest  itself. 
The  brain  may  be  only  the  medium  or  agent  for  conscious- 
ness and  not  its  real  cause.  But  whether  its  philosophy  is 
materialistic  or  spiritual,  it  bases  its  particular  point  of  view 
and  its  method  upon  the  observable  fact  of  correlations  be- 
tween consciousness  and  nervous  processes  in  the  brain.  It 
accordingly  takes  the  activity  of  the  nervous  tissue  as  its 
starting-point,  acquaints  itself  with  the  facts  of  the  anatomy, 
histology,  and  physiology  of  the  nervous  system,  and  at- 

*For  a  discussion  of  this  question  the  student  is  referred  to  "Mental  De- 
velopment in  the  Child  and  the  Race,"  by  James  Mark  Baldwin. 


6  PSYCHOLOGY 

tempts  to  find  out  what  happens  in  the  brain  when  we  are 
conscious,  or,  more  exactly,  to  find  out  what  the  correlations 
are  between  the  nervous  activities  on  the  one  hand  and  men- 
tal states  or  activities  on  the  other.  It  really  combines  a 
large  part  of  neurology  (that  which  has  to  do  with  the  higher 
brain  centres  and  their  connections)  with  psychology  proper. 
One  of  its  important  problems  is  the  localization  of  brain 
centres  for  the  different  conscious  processes.  For  example, 
it  finds  the  centre  for  sight  in  the  occipital  lobes  of  the  brain, 
the  centre  for  hearing  in  the  superior  convolution  of  the  tem- 
poral lobes,  and  so  on.  In  the  present  state  of  knowledge  of 
the  physiology  of  the  nervous  tissue  there  is  relatively  little 
known  concerning  the  nervous  action  in  the  brain.  At  the 
present  time,  then,  physiological  psychology  can  be  little 
more  than  the  statement  of  a  series  of  neurological  facts  on 
the  one  hand,  and  of  conscious  facts  on  the  other. 

Psychophysics  is  the  study  of  the  relations  which  exist 
between  consciousness  and  the  world  of  physical  objects 
which  are  capable  of  acting  as  sense-stimuli.  It  is  a  partner- 
ship between  physics  and  psychology,  and  is  included  under 
experimental  psychology  as  now  carried  on  in  the  psychologi- 
cal laboratory. 

Comparative  Psychology  has  taken  at  least  two  directions. 
In  some  quarters  it  has  been  identical  with  animal  psychology 
and  has  occupied  itself  with  the  comparison  of  the  mental 
life  found  in  the  various  types  of  animals.  This  might  well 
include  a  comparison  of  the  mental  life  of  the  animal  forms 
with  that  of  man,  but  this  is  a  problem  for  the  future.  A 
wider  significance  has  been  given  in  other  quarters  to  com- 
parative psychology  in  that  it  is  considered  as  a  comparison 
of  the  normal  human  adult  consciousness  with  that  found  in 
the  child,  in  abnormal  man,  in  social  groups,  and  in  animals 
respectively. 

The  Procedure  of  Psychology. — Although  the  array  of 
psychologies  seems  rather  long  and  perplexing,  the  matter 
becomes  really  very  simple  when  we  remember  that  they  are 


INTRODUCTORY  7 

all  studies  of  consciousness,  and  that  consciousness  is  found 
only  in  human  beings  and  animals.  Nearly  all  these  forms 
of  psychology  are  simply  special  methods,  or  points  of  view, 
used  in  the  study  of  animal  and  human  consciousness.  A 
general  psychology,  such  as  we  are  entering  upon,  takes  for 
its  subject-matter  the  highest  type  of  consciousness  —  that  of 
the  adult  human  being.  But  it  may  make  use  of  any  of  the 
different  special  methods  and  points  of  view,  or  even  of  the 
subject-matter  of  the  different  psychologies,  in  so  far  as  it  is 
helpful  in  understanding  the  mental  life  of  normal  man. 

The  fundamental  method  of  psychology  is  observation: 
first,  the  observation  of  the  mental  states  and  processes  tak- 
ing place  in  our  own  minds,  and  second,  the  observation  of 
the  behavior  of  others  by  means  of  which  we  may  infer  the 
presence  and  nature  of  their  mental  states.  These  two  forms 
of  observation  are  necessary  in  psychology.  Without  the 
first  we  could  never  have  an  intimate  first-hand  acquaintance 
with  the  facts  of  consciousness,  and  without  the  second  we 
would  know  nothing  of  consciousness  outside  our  own  minds. 

The  first  form  of  observation  gives  us  direct  knowledge 
of  our  own  conscious  life  and  has  been  termed  —  introspection^ 
i.  e.,  looking  within.  Introspection  is  the  observation  of  our 
own  mental  states.  This  self-observation  does  not,  however, 
presuppose  a  new  process  or  method  of  observation  intro- 
duced by  the  psychologist.  Introspection  does  not  differ 
fundamentally  from  the  observation  employed  in  the  other 
sciences.  The  difference  lies  only  in  the  material  upon  which 
it  works.  Introspection  in  psychology  is  observation  of  men- 
tal facts,  while  observation  in  the  other  sciences  is  observa- 
tion of  material  facts.  Introspection  has  sometimes  been 
taken  to  be  an  inner  consciousness  in  distinction  to  an  outer 
consciousness  which  knows  the  outer  world  of  objects.  But 
there  is  no  valid  ground  for  such  a  distinction.  All  conscious- 
ness, whether  it  be  awareness  of  mental  states  or  of  material 
objects,  is  of  the  same  character.  The  distinction  of  inner 
and  outer  has  no  meaning  when  applied  to  consciousness  it- 


PSYCHOLOGY 

self.  The  awareness  of  a  material  object  is  just  as  much 
inner  consciousness  as  the  awareness  of  a  mental  state.  Both 
are  contents  of  consciousness.  The  ability  to  introspect  im- 
proves with  training  and  practice.  The  novice  in  psychology 
is  quite  as  helpless  as  the  beginning  student  in  biology  when 
given  his  first  high-power  microscope.  Expertness  is  needed 
no  less  for  the  accurate  observation  of  mental  states  than  for 
the  accurate  observation  of  material  specimens  in  biology, 
physics,  or  chemistry. 

Objections  have  been  urged  against  introspection  as  a 
scientific  method  on  the  ground  that  its  results  cannot  be 
verified.  The  claim  has  been  made  that  the  results  of  intro- 
spection cannot  be  confirmed  because  no  one  can  observe 
directly  the  conscious  states  of  another.  On  the  other  hand, 
the  objects  of  material  sciences  are  said  to  be  common  prop- 
erty. Any  one  may  observe  them  and  confirm  the  reports  of 
others.  This  distinction  of  the  private  nature  of  consciousness 
and  the  public  nature  of  objects  is  not  as  far-reaching  as  it 
seems  at  first  sight.-  All  the  sciences  are  built  up  by  means 
of  observation.  But  every  observation  is  the  observation  of 
some  one  person.  The  observation  itself  is  always  a  private 
and  personal  affair.  Different  observations  can  be  brought 
together  and  made  to  agree  only  when  reduced  to  a  common 
unit  of  measurement.  By  means  of  this  unit  of  measurement 
uniformity  may  be  established,  and  this  is  the  most  important 
thing  in  all  observation.  In  the  material  sciences  the  uni- 
formities are  found  in  terms  of  units  of  quantity — the  milli- 
metre, the  gram,  et  cetera.  In  psychology  the  uniformities 
are  in  the  terms  of  quality — quality  of  experience.  The  units 
of  quality  are  descriptive  units,  or  language  symbols.  The 
facts  of  consciousness  discovered  by  means  of  introspection 
may  be  reduced  to  the  common  terms  of  descriptive  language. 
If  when  measured  by  these  common  terms  the  experiences  of 
different  observers  show  uniformity,  that  is  sufficient  verifi- 
cation. 

Restating  this  point,  we  may  say  that  the  so-called  mate- 


INTRODUCTORY  9 

rial  objects  of  the  sciences  always  fall  within  some  one's  pri- 
vate experience.  The  material  object  which  I  observe  is  my 
object,  and  the  material  object  which  you  observe  is  your 
object.  You  can  never  experience  my  object  and  I  can  never 
experience  your  object.  They  become  common  to  both  of 
us  only  when  they  are  described  in  the  same  terms,  i.  e.,  re- 
duced to  the  same  symbols.  Likewise,  my  consciousness  and 
your  consciousness  become  common  property  when  described 
and  communicated  through  the  medium  of  language.  The 
reliability  of  these  descriptions  depends,  of  course,  upon  the 
degree  of  accuracy  with  which  the  symbols  of  language  are 
used.  There  is,  to  be  sure,  greater  opportunity  for  variation 
and  error  in  the  language  description  of  psychical  facts  than 
in  the  quantitative  units  of  measurement  of  the  material 
sciences.  But  even  in  the  material  sciences  there  is  variation 
and  error.  No  two  observers  report  exactly  the  same  results 
from  the  observation  of  material  objects.  The  method  of  in- 
trospection in  psychology  and  the  method  of  observation 
employed  in  the  material  sciences  are  alike  in  their  funda- 
mental procedure.  They  both  reduce  the  results  of  individ- 
ual and  personal  observation  to  the  common  terms  of  mea- 
surement or  description,  and  by  means  of  the  uniformities 
discovered  verify  the  facts.  When  a  number  of  investigators 
co-operate  and  compare  the  results  of  their  introspection, 
and  repeat  them  again  and  again,  a  mass  of  cumulative  evi- 
dence is  obtained  that  is  entirely  trustworthy. 

Another  objection  to  introspection  has  been  offered  on 
the  ground  that  the  observation  of  mental  states  cannot  take 
place  without  changing  their  nature.  This  objection  is  based 
upon  the  assumption  that  the  consciousness  of  mental  states 
is  not  the  same  as  the  consciousness  of  material  objects. 
This  assumption,  as  we  have  seen,  is  not  well  founded.  We 
have  spoken  of  this  before,  but  let  us  remind  ourselves  again 
that  the  observation  of  mental  states  is  not  a  different  kind 
of  observation  from  that  by  which  we  know  the  material 
world.  The  physicist  interprets  his  experience  in  one  way 


10  PSYCHOLOGY 

and  the  psychologist  in  another,  but  the  interpretation  is  a 
construction  which  is  put  upon  the  experience  after  it  is  over. 
In  the  one  case  we  are  interested  in  the  experience  as  an 
object  belonging  to  an  independent  material  world.  In  the 
other  case  we  are  interested  in  the  experience  as  a  part  of 
our  consciousness.  At  the  moment  of  observation  both  the 
object  and  the  mental  state  are  given  in  our  awareness. 

The  second  form  of  observation  in  the  procedure  of  psy- 
chology supplements  introspection.  It  is  the  observation 
of  behavior.  From  these  external  manifestations  we  may 
not  only  infer  the  presence  of  consciousness,  but  its  nature. 
When  a  man  smiles  we  judge  that  he  is  pleased.  When  a 
young  child  cries  we  know  that  it  is  experiencing  pain.  We 
can  establish  the  fact  that  there  is  a  large  number  of  corre- 
spondences  between  the  two  series  of  events.  Bodily  move- 
ments  and  attitudes  are  the  outward  signs  of  conscious  states. 
The  quiver  of  the  eyelid,  the  tremor  of  the  muscles  about  the 
mouth,  the  faint  blush  upon  the  cheek,  the  peculiar  quality 
and  intonation  of  the  voice,  all  betray  to  the  practised  ob- 
server the  nature  of  the  conscious  states  back  of  them.  In 
young  children  and  animals  observation  of  behavior  is  the 
only  means  we  have  of  gaining  knowledge  of  their  mental 
states. 

Consciousness. — What  consciousness  ultimately  is  we  do 
not  know  any  more  than  we  know  what  life  ultimately  is. 
Many  theories  have  been  formed  about  its  real  or  intrinsic 
nature,  but  so  far  these  theories  have  been  of  little  value  to 
the  science  of  psychology.1 

When  the  psychologist  asserts  his  inability  to  define  con- 
sciousness ultimately  he  does  not  intend  to  imply  that  psy- 

1  Such  inquiry  really  belongs  within  the  province  of  metaphysics  and  not 
in  psychology.  We  may,  however,  note  two  opposing  theories  concerning  the 
ultimate  nature  of  consciousness  that  have  been  generally  held: 

1.  The  spiritualistic  hypothesis. 

2.  The  materialistic  hypothesis. 

The  spiritualistic  hypothesis  holds  consciousness  to  be  states  of  an  unex- 
tended  permanent  being  of  immaterial  or  spiritual  nature.  The  materialistic 


^•^J: 


*i 


INTRODUCTORY  I I 

chology  is  different  from  the  other  sciences  in  respect  to  the 
definition  of  its  fundamental  subject-matter.  No  science  is 
able  to  define  its  subject-matter  ultimately.  What  matter 
really  is  remains  as  great  a  mystery  as  ever,  even  though  the 
sciences  of  physics  and  chemistry  attempt  to  define  it  vari- 
ously in  terms  of  energy,  or  in  terms  of  the  atom,  the  ion,  or 
the  electron.  These  are  metaphysical  conceptions,  and  they 
tell  us  no  more  about  the  real  nature  of  matter  than  the  spir- 
itualistic or  the  materialistic  hypothesis  tells  us  about  the 
real  nature  of  consciousness.  Biology,  too,  is  unable  to  define 
life  ultimately,  although  it  has  been  tempted  into  metaphysi- 
cal speculation  about  it.  This  is  illustrated  by  the  attempt 
in  some  quarters  to  conceive  life  as  a  manifestation  of  "vital 
force" — a  principle  of  mysterious'  and  unfathomable  essence 
thought  to  be  the  cause  of  life  phenomena.  Even  the  at- 
tempt to  reduce  life  to  some  form  of  refined  chemical  reac- 
tion is  none  the  less  pure  speculation.  Just  as  the  material 
and  biological  sciences  have  now  given  up  speculation  about 
the  transcendental  nature  of  matter  and  life,  so  psychology 
no  longer  speculates  about  the  transcendental  nature  of  con- 
sciousness. 

While  we  are  unable  to  reduce  consciousness  to  anything 
more  fundamental  than  itself,  we  are  able  to  define  it  as 
observable  fact.  When  we  say  that  we  are  conscious  we 
mean  that  we  have  experiences  that  WP  know  Hirprtly  Every 
moment  of  our  waking  lives  we  are  conscious:  we  see  lights 
and  colors,  or  hear  sounds,  or  taste  foods,  feel  pleasures  or 
pains,  perceive  objects,  image  forms,  remember  past  events, 
or  form  judgments,  reason,  feel  glad  or  sad,  or  angry,  love  or 
hate,  resolve,  decide,  and  experience  impulses  to  act.  Any 
or  all  of  these  are  states  of  consciousness.  We  can  observe 
them  directly.  We  can  analyze  those  that  are  complex  into 

hypothesis  regards  consciousness  as  a  form  of  nerve-energy  which,  so  far,  we 
have  not  been  able  to  observe  and  measure.  But  whatever  the  metaphysical 
basis  of  consciousness  may  be,  the  facts  of  consciousness  remain  the  same  as 
far  as  observation  of  them  goes. 


12  PSYCHOLOGY 

simple  conscious  states  and  can  weave  them  into  a  system  of 
relationships. 

Some  of  the  earlier  English  psychologists  used  the  term 
consciousness  to  signify  awareness  of  one's  own  mental  states 
and  processes.  Locke  denned  it  as  the  "perception  of  what 
passes  in  a  man's  own  mind,"  and  Reed  as  "that  immediate 
knowledge  which  we  have  of  all  the  present  operations  of  our 
own  mind."  But  more  recently^  that  meaning Jias. been  dis- 

|carded_and  now  the  term  consciousness  is  used  tQjndicate  any 
and  alTmejitai^perierice^  rTaLQn^YJLllg^SaJCgj^ss^  of  our  own 
mental  states,  but  alsoq-wareness  of  objects  jmd  .relations  in 
theputer^  world;  not  only  the  mental  experience  of  man  but 
the  mental  experience_Qf  all  sentient  j>emgs. 

Subject-Object  Nature  of  Consciousness. — One  of  the 
most  troublesome  points  to  keep  clear  in  discussing  the  na- 
ture of  consciousness  is  the  distinction  which  we  are  logically 
forced  to  make  between  the  subject  side  of  consciousness  and 
the  object,  or  content,  side.  To  be  conscious  implies  some 
one  who  is  conscious.  To  have  a  sensation  or  thought  seems 
logically  to  involve  a  subject  to  which  the  sensation  or  thought 
is  presented.  What  thinks  the  thought?  What  has  and 
owns  the  sensation?  Professor  James's  answer,  "that  the 
thoughts  themselves  are  the  thinkers,"  does  not  satisfy  the 
logical  need  of  our  thinking.  This  question  appears  in  vari- 
ous forms  in  the  study  of  conscious  phenomena.  We  cannot 
attempt  really  to  answer  it  without  entering  the  field  of  meta- 
physics, but  psychology  has  the  right  to  make  any  assump- 
tion concerning  it  that  is  in  accord  with  the  facts  of  con- 
sciousness. The  spiritualistic  hypothesis  of  consciousness 
assumes  a  being  of  psychical  nature,  a  permanent  ego,  or 
knower,  to  which  all  consciousness  as  content  is  presented. 
This  double  aspect  of  consciousness  has  given  rise  to  two 
different  points  of  view  concerning  consciousness : 

fi.  Consciousness  as  the  act  of  the  subject. 
2.  Consciousness  as  content  of  experience. 
It  is  important  for  the  student  to  keep  clearly  in  mind 


INTRODUCTORY  13 

these  two  possible  meanings  of  consciousness,  because  in  psy- 
chology the  term  is  sometimes  used  in  one  sense  and  some- 
times in  the  other,  and  often  the  meanings  are  confused. 
The  first  meaning  considers  only  the  subject  and  its  activity 
in  attending,  perceiving,  feeling,  willing,  et  cetera.  The  sec- 
ond meaning  considers  only  the  content  of  experience,  or,  in 
common  terms,  that  which  is  experienced — a  sensation,  a 
percept,  a  memory  image,  an  emotion,  et  cetera.  For  exam- 
ple, the  content  of  consciousness  is  that  which  is  presented  to 
us  as  different  experiences.  The  experience  of  red  is  different 
from  that  of  green.  The  experience  of  the  taste  of  sugar  is 
different  from  the  experience  of  the  sound  of  middle  C  on  the 
piano.  The  experience  of  an  emotion  is  different  from  the 
experience  of  a  memory  image.  Such  experiences  make  up 
the  content  of  consciousness. 

It  is  not  possible  in  an  introductory  psychology  to  avoid 
the  use  of  consciousness  as  subject  and  consciousness  as  con- 
tent, but  it  is  possible  to  know  when  we  are  using  the  one 
and  when  the  other.  As  an  illustration  of  the  two  meanings 
of  consciousness  found  in  the  literature  of  psychology  we  may 
instance  the  widely  differing  definitions  offered  for  some  of 
the  most  common  concepts.  For  example,  if  the  student  will 
read  the  definitions  of  attention  in  a  number  of  text-books  on 
psychology,  he  will  find  that  in  some  attention  is  defined  as 

the   "power  Of  the  mind   to   COnrentrfltp     s^Wf^    anrj  prolong 

consciousness,"  while  in  others  it  is  defined  as  " clearness,, 
vividness,  or  distinctness  of  mental  content,  accompanied 
by  a  complex  of  muscular  strain  and  effort."  It  is  plain  that 
in  the  former  case  consciousness  is  conceived  as  a  subject  or 
agent  manipulating  the  contents  of  its  experience,  while  in 
the  latter  case  consciousness  is  merely  content. 

It  is  the  content  side  of  consciousness  which  furnishes  the 
facts  of  scientific  psychology,  because  the  content  of  our  ex- 
perience is  the  only  part  of  consciousness  that  lends  itself  to 
observation.  It  is  the  only  part  about  which  we  can  have 
definite,  empirical  knowledge.  On  the  other  hand,  the  so- 


14  PSYCHOLOGY 

called  subject  of  consciousness  always  lies  outside  the  world 
of  observable  facts.  It  is  a  logical  construction  which  should 
be  used  in  psychology  only  as  a  convenient  hypothesis.  In 
referring  to  the  subject  of  consciousness  as  a  logical  construc- 
tion, we  mean  that  it  is  a  factor  which  appears  only  after  we 
begin  to  think  about  the  facts  of  consciousness  and  attempt 
to  explain  them  rationally.  It  is,  therefore,  a  product  of 
thought,  and  not  a  directly  observable  reality. 

Those  who  have  attempted  to  avoid  the  hypothesis  of  a 
spiritualistic  subject  of  consciousness  or  have  denied  its  exis- 
tence, usually  substitute  for  it  the  assumption  that  conscious- 
ness is  really  some  form  of  nervous  energy.  They  assert  that 
there  is  no  necessity  of  assuming  anything  more  than  this 
nervous  energy  in  a  living  and  acting  brain  to  account  for  the 
phenomena  of  consciousness.  Whether  we  accept  the  hy- 
pothesis of  a  psychical  or  spiritual  subject  of  consciousness, 
or  that  of  the  material  nature  of  consciousness,  really  makes 
little  difference  within  psychology  itself  so  long  as  we  are 
consistent  in  holding  to  one  or  the  other.  The  observable 
facts  remain  the  same  in  either  case.  The  sensation  of  red 
is  just  what  it  is  experienced  to  be,  whether  it  is  referred  to 
a  psychical  subject  or  to  a  form  of  nervous  energy.  If  con- 
sciousness is  a  form  of  nervous  energy,  then  the  brain  or 
nervous  system  is  the  unifying  principle  which  has  and  owns 
the  conscious  states.  Now,  we  know  by  actual  observation 
that  conscious  states  as  content  of  experience  exist  only  at 
the  moment  of  their  experience.  Then,  according  to  the 
materialistic  conception,  they  become,  when  they  cease  to 
be  experienced,  merely  states  or  conditions  of  the  nervous 
system.  They  may  be  revived  again  when  the  nervous  ma- 
terial which  has  given  rise  to  them  is  stimulated  into  activity. 

rThis  conception  tacitly  assumes  a  mode  of  transformation  be- 
tween material  brain  processes  and  conscious  experience  that 

I  is  beyond  the  realm  of  observable  fact.  Even  if  it  were  pos- 
sible to  observe  all  the  details  of  the  brain-cell  processes,  and 
to  follow  them  to  their  last  chemical  or  physical  activities. 


INTRODUCTORY  1 5 

they  would  still  be  just  what  they  are — material  processes. 
The  particular  manner  or  mode  of  their  transformation  into 
conscious  states  is  never  revealed  to  us  as  observable  fact. 
The  central  point  in  this  materialistic  hypothesis  is  the  asser- 
tion that  conscious  states  are  really  and  ultimately  some  form 
(of  nervous  energy  in  the  brain,  and  that  therefore  the  brain 
is  the  ultimate  ground  of  existence  for  all  consciousness. 

The  student  should  not  confuse  this  assumption  with  the 
observable  fact  of  the  dependence  of  conscious  phenomena 
upon  the  brain  or  nervous  system  in  a  living  organism.  The 
assumption  attempts  to  explain  the  ultimate  or  real  nature 
of  consciousness  by  reducing  it  to  nervous  energy.  On  the 
other  hand,  the  establishment  of  the  fact  of  the  dependence 
of  consciousness  upon  the  nervous  system  does  not  involve 
the  question  of  what  its  ultimate  ground  of  being  is,  but 
rests  its  case  upon  the  observable  facts  of  consciousness  on 
the  one  hand,  and  the  observable  facts  of  brain  states  and 
activities  on  the  other. 

Soul. — In  popular  thought  it  is  often  the  soul  which  plays 
the  part  of  the  subject  of  consciousness.  Here  we  meet  the 
idea  that  it  is  the  soul  that  knows  and  feels  and  wills.  But 
the  popular  conception  of  the  soul  really  involves  so  many 
transcendental  and  metaphysical  attributes  that  it  cannot  be 
used  profitably  in  psychology.  If  the  term  is  used  at  all 
there,  as  it  oftentimes  is,  it  must  be  shorn  of  many  of  its 
metaphysical  implications  and  made  identical  with  the  mere 
subject  of  consciousness.  The  old  and  popular  meanings 
are  apt,  however,  to  associate  themselves  with  its  use,  even 
in  a  restricted  sense.  So  it- is  better  to  avoid  the  term  in 
psychology.1 

Singularly  enough  the  term  soul  has  sometimes  been  used 
to  signify  the  content  side  of  consciousness.  This  concep- 
tion makes  it  the  sum  total  of  one's  thoughts  and  feelings. 
But  this  is  altogether  unjustifiable,  because  it  twists  the  term 

1  It  is  a  narrow  and  pedantic  view  which  for  this  reason  denies  its  existence 
as  an  ultimate  reality. 


i6 


PSYCHOLOGY 


too  far  from  its  popular  and  original  meaning.  Its  use  as  the 
subject  of  consciousness  is  preferable,  for  then  it  retains  some 
of  its  old  meaning  as  a  permanent  being,  or  entity,  behind  our 
-consciousness  experiences. 

Mind. — The  double  aspect  of  consciousness  appears  again 
when  we  try  to  get  a  clear  idea  of  what  is  meant  by  mind. 
Very  commonly  it  is  used  to  designate  that  which  owns  the 
conscious  states.  Thus  we  speak  of  a  sensation,  a  perception, 
an  image,  a  feeling,  or  an  emotion  as  in  the  mind,  or  we  may 
say  that  the  mind  has  the  sensation,  the  perception,  et  cetera. 
In  this  way  we  think  of  the  mind  as  a  continuous,  if  not  per- 
manent, psychical  being  persisting  through  the  varying  states 
of  consciousness  and  holding  them  together,  and  possessing 
powers,  capacities,  attributes,  and  dispositions  which  are  al- 
ways in  existence,  even  when  not  active.  Used  in  this  sense, 
it  turns  out  to  be  the  same  conception  as  that  of  the  subject 
or  knower  of  consciousness,  and  it  is  therefore  metaphysical 
in  its  real  meaning.  In  this  sense  the  mind  is  that  something 
that  knows  and  feels  and  wills,  but  what  that  something  is, 
is  never  given  to  us  as  an  observable  fact. 

On  the  content  side  of  consciousness  mind  is  the  sum  total 
of  all  our  mental  states.  Sensations,  images,  memories,  judg- 
ments, feelings,  desires,  volitions,  et  cetera — all  these  organ- 
ized, systematized,  and  unified  in  such  a  way  that  they  hang 
together  as  an  individual  whole.  This  is  the  mind  that  we 
know  directly.  Since,  however,  the  content  of  experience  is 
known  only  in  the  present  moment,  and  since  each  present- 
moment  experience  is  in  a  way  separate  from  all  others,  we 
might  think  at  first  glance  that  there  could  be  no  unity  or 
organization  in  the  contents  of  experience  themselves,  and 
that  without  a  unifying  subject  the  contents  of  consciousness 
would  remain  a  mere  series  of  isolated  bits,  strung  out  in  a 
time  sequence.  In  fact  we  very  frequently  find  references 
to  the  subject  of  consciousness  as  that  something,  the  sole 
function  of  which  is  to  organize  the  various  elements  of  our 
experience  into  some  sort  of  unity.  Without  this  something 


INTRODUCTORY  17 

it  is  claimed  that  no  organization  or  unity  can  exist.  But 
the  present  moments  of  experience  do  contain  actual  and 
observable  material  which  binds  them  together.  For  in- 
stance, if  I  recognize  a  man  to-day  whom  I  met  last  week,  the  | 
present  moment  of  consciousness  has  in  it  not  only  the  pres- 
entation of  the  man  to-day,  but  the  memory  of  the  man  last  > 
week.  Thus  the  present-moment  experience  has  in  it  as  a 
part  of  its  content  the  element  of  memory  which  binds  it  to 
the  past  experience.  Recognition  is  present  in  the  sensory 
presentation  of  the  man  to-day  as  a  consciousness  of  familiar- 
ity which  relates  the  present  content  to  past  content.  In  a 
full  and  complete  recognition  there  is  consciousness  of  the 
identity  in  the  two  experiences,  and  of  the  time  relationship 
between  them.  Moreover,  the  two  experiences  fall  within  a 
larger  and  relatively  unchanging  content  which  we  shall  dis- 
cuss later  as  the  self.  This  larger  content  is  always  involved 
in  any  single  experience  incorporating  it  within  a  system  of 
conscious  relationships.  Therefore  —  no  single 
stands  by  itself  even  on  the  content,  side  of 


While  the  experiences  appear  to  come  to  the  individual  in  a 
series  of  sequences,  they  really  interpenetrate  each  other  and 
form  an  organized  continuum. 

Self  .—On  the  subject  side  of  consciousness  self,  mind,  and 
subject  are  really  synonymous  terms.  The  subject  self  is  that 
which  persists  through  all  the  changing  experiences  of  the 
individual  and  is  therefore  the  psychical  being  to  which  all 
these  experiences  are  presented.  Like  .the  mind,  it  is  sup- 
posed to  possess  powers,  capacities,  attributes,  and  disposi- 
tions which  account  for  its  outward  and  observable  charac- 
teristics and  manifestations. 

But  on  the  content  side  of  consciousness  the  self  is  the 
most  central,  intimate,  and  persistent  core  of  experience  of 
an  individual  —  those  experiences  which  form  the  complex 
mass  of  conscious  content  not  always  directly  attended  to, 
but  subconsciously  present;  that  content  which  changes 
slowly  but  grows  and  develops  as  we  become  more  familiar 


I 8  PSYCHOLOGY 

with  our  own  nature  and  the  world  about  us.  It  is  made  up 
of  our  bodily  sensations  and  sensuous  appetites,  our  private 
feelings  and  insistent  memories,  our  real  desires  and  familiar 
thoughts  and  ideas.  These  elements  are  not  all  present  at 
any  one  moment,  but  change  with  the  changes  of  our  daily 
life.  The  organic  or  bodily  sensations  and  feelings  are,  how- 
ever, fairly  constant,  and  form  a  relatively  permanent  centre 
about  which  the  other  self-contents  revolve.  Sometimes  one 
and  sometimes  another  group  of  experiences  combines  with 
this  constant  factor  of  bodily  sensations,  and  thereby  makes 
up  the  changing  aspects  of  the  self.  The  business  man  leaves 
his  family  self  behind  and  puts  on  another  self  when  he  enters 
upon  the  duties  of  the  day.  He  passes  from  one  set  of  habit- 
ual and  familiar  background  experiences  to  another.  He 
shows  a  different  side  of  his  character  at  the  club,  on  the 
golf-links,  or  at  an  evening  reception.  Yet  there  is  a  certain 
identity  running  through  these  different  groups  of  self-expe- 
riences which  unifies  them  into  a  single  system  of  experience. 
Certain  of  these  experiences  are  more  persistent  than  others, 
and  form  a  background  against  which  all  new  experiences  are 
projected. 

Although,  as  we  have  seen,  the  terms  mind  and  self  point 
out  the  same  ultimate  reality,  as  subject  of  consciousness, 
they  are  used  with  different  meanings  or  restrictions.  As  far 
as  the  naive  metaphysics  of  psychology  go  there  is  practically 
no  differentiation  between  the  mind  and  self.  They  are  both 
the  subject  which  knows  and  feels  and  wills,  and  whatever 
powers  and  attributes  are  assumed  for  the  one  are  usually 
attributed  to  the  other.  But  on  the  content  side  of  con- 
sciousness there  is  a  definite  limitation.  Mind  is  an  organiza- 
tion and  unity  of  conscious  content  in  an  individual,  while  self 
is  a  central  group  within  the  larger  organization  of  the  mind. 

The  preceding  discussion  has  made  plain  the  fact  that 
there  are  two  distinct  tendencies  in  psychology — the  philo- 
sophical and  empirical.  The  one  leads  us  into  the  world  of 
speculation  and  metaphysical  reality.  The  other  limits  us 


INTRODUCTORY  19 

to  the  world  of  observable  facts.  The  one  induces  us  to 
infer  and  beb'eve  in  the  existence  of  an  enduring  ego,  mind,  or 
soul.  The  other  deals  only  with  the  observable  content  of 
consciousness.  The  one  appeals  to  our  interest  in  the  larger 
problem  of  the  ultimate  reality  and  meaning  of  our  experi- 
ences. The  other  limits  us  to  an  arbitrarily  chosen  field  of 
facts — the  facts  of  consciousness  which  are  abstracted  only 
for  the  purpose  of  study.  While  it  is  our  desire  to  follow 
the  empirical  tendency,  it  is  not  our  intention  thereby  to 
take  away,  or  even  to  diminish  the  student's  interest  in  the 
question  of  the  ultimate  nature  of  consciousness.  What  con- 
sciousness really  is,  how  it  came  to  exist,  and  what  .its  place 
is  in  the  universe — -are  questions  worthy  of  our  higher  reason 
and  philosophical  insight.  No  petty  round  of  facts  ought  to 
ensnare  and  tame  man's  desire  to  know  the  whole  truth.  We 
believe  that  the  world  is  larger  than  the  facts  given  us  by 
the  methods  of  science.  But  before  we  attempt  to  take  the 
broader  outlook,  our  first  task  is  to  master  the  facts  just  as  they 
are  given  to  us — to  pick  out  those  that  are  significant  and  to 
analyze  them  into  their  elements  and  find  out  the  laws  that 
govern  their  behavior,  to  evaluate  them  properly  and  or- 
ganize them  into  a  system.  This  is  the  task  that  empirical 
psychology  sets  before  itself. 

In  a  general  study  of  human  consciousness  such  as  we  are 
going  to  undertake  there  are  several  points  of  view  to  be 
kept  in  mind : 

1.  Conscious  states  must  be  analyzed  and  described.     In 
doing  this  we  take  the  structural  point  of  view  and  ignore 
the  functional  aspect  of  consciousness. 

2.  We  must  point  out  the  laws  of  mental  activity  accord- 
ing to  which  conscious  states  conjoin  and  form  streams  of 
thought  or  feeling.     Here  consciousness  is  considered  as  a 
process  and  the  point  of  view  is  functional. 

3.  The  relation  of  consciousness  to  the  brain  and  its  nerve 
processes  should  be  determined.     When  we  attempt  to  do 
this  our  point  of  view  is  physiological. 


2O  PSYCHOLOGY 

4.  Changes  in  consciousness  that  accompany  changes  in 
the  physical  world  which  act  as  stimuli  should  be  noted. 
This  demands  the  psychophysical  point  of  view. 

5.  Finally  we  must  not  neglect  the  relation  of  conscious- 
ness to  behavior. 

We  shall  not  attempt  to  follow  these  points  of  view  sep- 
arately. Sometimes  one  and  sometimes  another  will  be 
uppermost  in  the  following  discussions. 


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^ 

THE  NERVOUS   SYSTEM 

^Jk_  3  ^   ,-3  1  -  y  ^  — *-*>  ~  "f?"  eT"Z-- 

Although  the  study  of  the  structure  and  function  of  the 
nervous  system  is  not  properly  a  part  of  psychology,  it  is, 
nevertheless,  important  for  the  understanding  of  the  processes 
of  conscious  life  to  know  something  of  the  elementary  facts 
in  the  anajtomy,  histology,  and  physiology  of  the  brain.  This 
seems  necessary  since  we  assume  that  all  consciousness  is  in 
some  way  dependent  upon  the  action  of  the  nervous  system. 

The  brain  is  connected  through  nerve-fibres  with  all  part^ 
of  the  body.  Some  of  these  fibres  (sensory  fibres)  come  from 
the  sense  end-organs  which  are  played  upon  by  the  external 
forces  in  the  environment,  and  some  of  them  (motor  fibres)/ 
go  out  to  the  muscles  which  bring  about  adaptive  movements/ 
of  the  body.  Biologically  the  brain  and  its  nerve-connec- 
tions are  merely  the  means  through  which  external  stimula- 
tions are  transformed  into  organic  behavior.  Changes  in  the 
outer  world  act  upon  the  sensory  nerve-ends  and  set  up 
nerve-impulses  which  are  carried  to  the  brain,  where  they 
are  projected  outward  into  appropriate  muscular  and  glandu- 
lar activities. 

But  accompanying  these  physiological  brain  and  nerve 
processes  there  is  something  else  which  is  not  discoverable  in 
them,  and  of  which  physiology  can  take  no  account,  however 
much  its  methods  may  be  refined  and  perfected.  This  some- 
thing is  consciousness.  When  light-rays  strike  the  retina  we 
see.  When  air-vibrations  enter  the  ear  we  hear.  Besides 
the  sensations  which  arise  when  external  objects  stimulate 
the  sensory  end-organs  there  are  other  conscious  experiences 
which  accompany  the  neural  processes  within  the  brain. 
These  experiences  are  the  higher  conscious  states  of  percep- 
tion, imagination,  memory,  judgment,  reason,  feelings,  emo- 


22  PSYCHOLOGY 

tiong,  etc.  Although  conscious  states  depend  upon  brain 
states,  we  must  not  confuse  these  two  forms  of  existence — 
the  mental  and  the  physical.  Consciousness  is  not  the  brain, 
or  any  of  its  neural  processes.  "Even  though  we  were  able  to 
follow  and  observe  a  nerve-activity  to  its  last  analysis  within 
the  brain-cells,  we  could  never  discover  an  element  of  con- 
sciousness in  it.  What  the  exact  relation  between  the  mind 
and  the  brain  is  we  do  not  know.  We  can  only  assert  that 
the  mind  is  dependent  upon  certain  brain-activities. 

Consciousness  and  the  Nervous  System. — There  are  sev- 
eral groups  of  facts  which  indicate  the  dependence  of  con- 
sciousness upon  the  nervous  system: 

1 .  Consciousness  depends  upon  the  action  of  sense-organs. 
Without  the  sensitive  nerve-endings  in  eye,  ear,  nose,  mouth, 
skin,  and  deeper  tissues  of  the  body,  we  could  never  be  aware 
of  anything.     All  the  higher  forms  of  consciousness  are  based 
upon  the  sensory  experiences  which  are  mediated  by  the 
nerve-endings  in  the  sense-organs. 

2.  Certain  drugs,  like  alcohol,  ether,  hashish,  etc.,  which 
disturb  the  action  of  the  nervous  tissue  in  the  brain,  also 
affect  consciousness. 

3.  Bodily  diseases,  especially  those  producing  high  fever, 
seriously  interfere  with  the  conscious  processes. 

4.  Diseased  conditions  of  the  brain — tumors,  brain-hem- 
orrhages, lesions,  disintegration  of  the  nervous  tissue,  etc., 
are  followed  by  disturbances  or  loss  of  certain  forms  of  con- 
sciousness.    Thus  a  tumor  in  the  occipital  region  of  the  brain 
may  cause  the  loss  of  visual  memories.     A  lesion  in  the  left 
temporal  lobe  is  followed  by  the  loss  of  the  ability  to  under- 
stand spoken  words. 

5.  If  we  compare  the  different  forms  of  animal  life,  from 
the  lowest  to  the  highest,  we  find  that  the  most  highly  devel- 
oped consciousness  goes  with  the  most  complex  and  highly 
developed  nervous  system. 

Development  of  the  Central  Nervous  System. — The  cen- 
tral nervous  system  is  made  up  of  the  brain  and  the  spinal 


THE   NERVOUS   SYSTEM 


cord.  The  brain  is  the  mass  of  nerve-tissue  found  within  the 
cranial  case,  while  the  spinal  cord  is  the  long  tube  of  nervous 
tissue  within  the  vertebral  canal.  The  brain  sends  out  twelve 
pairs  of  cranial  nerves  whose  fibres  go  to  the  sense-organs 
and  muscles  of  the  head,  face,  and  some  of  the  vital  organs 
of  the  body.  From  the  spinal  cord 
issue  thirty-one  pairs  of  spinal  nerves 
whose  fibres  go  to  the  sensory  sur- 
faces and  muscles  of  the  body.  The 
cranial  and  spinal  nerves  are  com- 
posed of  sensory  and  motor  fibres 
which  constitute  the  afferent  and  ef- 
ferent pathways  between  the  body  and 
the  central  nervous  system. 

We  can  best  understand  the  struc- 
ture of  the  nervous  system  by  follow- 
ing its  embryological  growth.  Nerve- 
tissue  develops  from  the  ectoderm_or 
outer  layer  of  embryonic  cells.  Very 
early  in  the  growth  of  the  embryo, 
after  it  has  elongated,  a  longitudinal 

groove,  the  medullary  groove,  forms  in  the  medullary  plate, 
or  beginning  nerve-tissue.  The  edges  of  this  groove  come 
together  and  form  the  neural  tube,  which  extends  along  the 
length  of  the  vertebral  column  and  into  the  cranial  cavity. 

The  cavity  enclosed  within  the  neural  tube  is  the  spinal 
canal.  This  canal,  at  its  upper  extremity,  later  forms  the 
irregular  ventricles  of  the  brain.  The  walls  of  the  upper,  or 
anterior  part  of  the  neural  tube  thicken  enormously  and  form 
the  brain.  The  walls  of  the  lower  part  thicken  to  a  less 
degree  but  more  uniformly  and  form  the  spinal  cord.  Within 
the  cranial  cavity  the  neural  tube  forms  by  ring-like  constric- 
tions and  dilatations  into  three  primary  brain  vesicles,  known 
as  anterior,  middle,  and  posterior  vesicles.  These  three  pri- 
mary vesicles  give  rise  to  the  fore-brain,  mid-brain,  and  hind- 
brain  respectively. 


Medullary  plate 


Medullary  groove 

/  ^--Medullary  ridge 


Medullary  tube 
Central  canal 


FIG.  i . — Diagram  repre- 
senting the  formation 
of  the  medullary  tube 
from  the  outer  germ- 
layer. 

(Taken  from  Villager's  "Brain 
and  Spinal  Cord.") 


Mid-brain, 
vesicle 


fore-brain 
vesicle 


find-brain 
vesicle 


Thalamus 

Mid-brain 
Cerebellum 

Medulla 
oblong  at  a 


Spinal  cord 


FIG.  2. — A,  Diagram  showing  the  brain- vesicles;  B,  Diagram  showing  parts 
of  embryonic  brain 


Cerebrum 


Lateral 
Ventricle 


Cerebellum 


Spinal  cord 


Aqueduct  of 
Sylvius 


IV  Ventricle 


Spinal  canal 


FIG.  3. — Diagram  showing  the  brain- ventricles 


THE  NERVOUS   SYSTEM 


/Fore 
/Brain 


Brain./ 


Hind 
Brain 


Cord 


FIG.  4. — Diagram  showing  a  cross-section  of  the  brain.     (Highly  diagramatic.) 

{  Olfactory  bulbs  and  tracts.  ^ 

j  Cerebral  hemispheres.  ' 
( Anterior     <  „  ,  .  ,     ^ 

Corpora  stnata.'^ 

{  Lateral  ventricles. 


Neural  tube    • 


Fore-brain 


Posterior 


f  Pineal  body.  • 
I  Thalami.  — 
J  Optic  tracts.   — 
Third  ventricle. 


u 

[  Corpora  quadrigemina.- 
Mid-brain J  Crura 


Hind-brain. 


Aqueduct  of  Sylvius. 

Pons  Varolii. 
Medulla  oblongata.. 
Cerebellum. 
Fourth  ventricle. 


\  Spinal  cord. 


20  PSYCHOLOGY 

The  Gross  Structure  of  the  Brain. — The  brain  is  divided 

a  median  fissure  into  two  symmetrical  hemispheres.  The 
division  is  not  complete,  however,  for  at  the  bottom  of  the 
fissure  a  broad  band  of  fibres,  the  corpus  callosum ,  unites 
the  two  halves  of  the  brain.  The  median  fissure  extends  the 
whole  length  of  the  cord  and  divides  it  less  prominently  into 
right  and  left  halves. 

The  surface  of  the  brain  is  furrowed  by  fissures  or  sutci, 
which  serve  to  increase  the  cortical  area.  The  ridges  be- 
tween the  fissures  are  called  convolutions.  Two  of  the  fis- 
^ures,  deeper  than  all  the  others,  make  convenient  landmarks 

each  cerebral  hemisphere.     They  are  the  lateral  fissure 
ssure  of  Sylvius)  and  the  central  fissure  (fissure  of  Rolando) . 

It  is  sometimes  convenient  to  divide  each  cerebral  hemi- 
sphere into  lobes.  The  frontal  lobe  occupies  the  anterior,  the 
occipital  lobe  the  posterior,  the  fcajz&al  lobe  the  upper  central, 
and  the  temporal  lobe  the  lower/central  part  of  the  cerebral 
The  island  of^Reil  forms  the  fifth  lobe  of  the 
cereb^atnemiaphorc.-^ 

he  cerebellum,  sometimes  called  the  little  brain,  lies 
below  the  cerebrum  on  the  dorsal  side  of  the  brain.  Below 
and  in  front  of  the  cerebellum  is  the  medulla  oblongata,  which 
is  an  enlargement  of  the  spinal  cord  at  its  upper  end.  Almost 
encircling  the  medulla  oblongata  is  the  pons,  a  thick  band  of 
fibres  joining  the  two  halves  of  the  cerebellum. 

The  cerebral  hemispheres  are  the  largest  and  most  con- 
spicuous parts  of  the  fore-brain.  The  other  principal  parts, 
the  corpora  striata,  the  pineal  body,  and  the  thalami,  are  over- 
laid and  concealed  from  view  by  the  folds  of  the  cerebral 
hemispheres.  The  hemispheres  also  enfold  the  parts  of  the 
mid-brain,  the  corpora  quadrigemina,  and  the  critra  cerebri, 
which  lie  below  the  thalami.  The  pons,  medulla,  inid-brain, 
and  thalami  constitute  the  brain-stem.  A  medial  Cross-sec- 
tion of  the  brain  will  shbw  all  these  parts  except  theVorpora 
striata.  \ 

From  the  ventral  and  basal  side  of  the  brain  are  given 


Cer. 


FIG.  s- — The  figure  on  the  left  shows 

the  general  relations  of  the  central 

nervous  system  to  the  bones  of  the 

skull  and  spine.     The  figure  on  the 

right  displays  the  general  contours  of 

the  central  system  as  seen  from  in 

front.     The  great  ganglionated  cord 

of  the  sympathetic  system  is  shown 

attached   to   one   side   of   the   spinal 

nerves;    the  other  side  has  been  cut 

away.    Cer.,  the  cerebral  hemispheres; 

O,  the  olfactory  centres;   P,  the  pons 

Varolii;    M,  trte  medulla,  oblongata; 

Cb.,  the  cerebellum;   Sp-C.,  the  spinal 

cord;   /,  the  olfactory  nerve;   //,  the 

optic    nerve;     ///,    the    oculo-motor 

nerve;    IV,  the  trochlear  nerve;    V, 

the  trigeminus  nerve;    VI,  abducens 

nerve;    VII,  the  facial  nf-rve;    VIII, 

the    auditory     nerve;      7.Y,     glosso- 

pharyngeal    nerve;      X.     the    vagus  _X^ 

nerve;  XI,  spinal  accessory;  XII, 
the  hypoglossal  nerve;  C,  the  first  cervical  spinal  nerve;  Di.  the  first  dorsal,  or  thoracic,  nerve;  L\,  the  first 
lumbarnerve;  Si,  the  first  sacral  nerve;  X\,  filum  terminale;  CS',  superior  cervical  ganglion  of  the  sympathetic; 
CS1,  middle  cervical  ganglion  of  the  sympathetic;  CS*,  and  DS1,  junction  of  the  inferior  cervical  and  the  first 
dorsal,  or  thoracic,  ganglion  of  the  sympathetic;  /AS'11,  the  eleventh  dorsal,  or  thoracic  ganglion,  of  the  sym- 
pathetic; LS1.  'the  first  lumbar  ganglion  of  the  same  system;  SS',  the  first  sacral  ganglion  also  of  the  sym- 
pathetic 

(From  Anvil's  "  Psychology.") 


Frontal  lobe 


Preccntral  gyre 
Central  fissure 


Parietal  lobe 


Occipital  lobe 


FIG.  6. — The  upper  surface  of  the  cerebral  hemispheres. 
(From  Ladd  and  Woodworth,  after  Sobotta-McMurrich.) 


Central  fissure 


Superior 

frontal  gyre 

Middle 

frontal  gyre 

Precentral 

gyre 

Inferior 
frontal  gyre 


Supramarginal  gyre 
'  ngular  gyre 


Superior 

temporal 

gyre 

Middle 

temporal 

gyre 

Inferior 

temporal 

gy/e 

Cerebellum 


Fissure  of  Sylvius 


FIG.  7. — Lateral  surface  of  the  left  cerebral  hemisphere. 
(From  Ladd  and  Woodworth,  after  Edinger.) 


Paracentral  lobule 

Cingulate  fissure     Central  fissure      /       D 

*  /          Precune 


Lirnbic  lobe 


Optic  chiasm    Mammillary 

body 

FlG.  8. — Mesial  surface  of  the  right  cerebral  hemisphere. 
(From  Ladd  and  Woodworth,  after  Edinger.) 


FIG.  9. — Under  surface  of  the  brain.  (From  Ladd  and  Woodworth,  after  Van  Gehuchten.)  The 
Roman  numerals  at  the  left  margin  of  the  figure  indicate  the  twelve  cranial  nerves;  hyp,  hy- 
pophysis; ch,  optic  chiasm;  c.  mam.,  mammillary  body;  PC,  peduncle  of  the  cerebrum;  pr,  pons; 
o,  olive;  py,  pyramids;  CI,  first  spinal  nerve. 

29 


*u  ** 

the  twelve  pairs  of  cranial  nerves.  Some  of  tnfcse  nerves  carry 
only  sensory  fibres,  some  only  motor  fibres,  while  others  carry 
sensory  and  motor  fibres  (mixed  nerves)  . 

~ 


NAMES    AND    GENERAL    FUNCTION    OF    THE 
NIAL   NERVES 

Olfactory:  Sensory  fibres  from  olfactory  sense-organs. 
Optic:  Sensory  fibres  from  the  visual  sense-organs. 
Oculo-motor :  Motor  fibres  to  several  muscles  of  eyes. 
Trochlear :  Motor  fibres  to  superior  oblique  muscles  of  eyes. 
Trigeminal:  Sensory   fibres   from    cutaneous   sense-organs   of 
i>^)  face,  scalp,  mouth,  tongue,  and  teeth. 
"V^      >Motor  fibres  to  muscles  of  mastication. 
VI.     Abducens:  Motor  fibres  to  external  rectus  muscles  of  eyes. 
VII.     Facial:  Sensory  fibres  from  gustatory  end-organs  in  tongue. 

Motor  fibres  to  muscles  of  face,  scalp,  and  external  ears. 
VIII.     Auditory:  Sensory  fibres  from  auditory  end-organs  in  cochlea 
(cochlear   branch),  and   from  semicircular  canals  of  ear 
Vr*wV*tvestiDvuar  branch). 
IX.     Glossopharyngeal:  Sensory  fibres  from  gustatory  end-organs. 

Motor  fibres  to  tongue  and  pharynx. 

X.     Pneumogastric,  or  vagus:  Sensory  fibres  from  respiratory,  cir- 
culatory, and  digestive  organs. 

Motor  fibres  to  pharynx,  larynx,  oesophagus,  stomach,  respi- 
ratory organs,  and  intestines,  also  inhibitory  fibres  to 
heart. 
XI.     Spinal-accessory:  Motor  fibres  to  muscles  of  neck  and  shoulders. 

XjJ.     Hypoglossal:  Motor  fibres  to  muscles  of  tongue. 
**W£v    PV^^L. 

^F  The  spinal  nerves  (31  pairs)  are  given  off  from  the  sides  of 

spinal  cord.     Each  nerve  is  attached,  to  .the  corxUby  two 
f*  .  Ar*V**rp  »nl  V-HV*^AX*^    J     . 

V    roots — a  posterior  root  and  an  ^mfcerior  foot.    'The  posterior 

jT  root  is  composed  chiefly  of  sensorynEres  from  cell-bodies  in 
the  spinal  ganglia.  The  anterior  root  is  composed  of  motor 
fibres  whose  cell-bodies  lie  within  the  gray  matter  of  the 
cord.  The  two  roots  join  shortly  after  leaving  the  cord  and 
form  a  complete  spinal  nerve.  The  spinal  nerves  are  divided 
into  cejyjcjJL(&4jairs),  thoracic  (12  pairs),  lumbar  (5  pairs), 
sacral(5  pairs),  and 


_—      ">        Q  lX*<ui£/U0Jc  "*    (_&•«-*•    <Xift>Vvfl^».  Q,o« 

THE   NERVOUS   SYSTEM  31 

The  brain,  the  cord,  the  cranial  nerves,  and  the  spinal 
nerves  make  up  the  cerebro-spinal  nervous  system.         1 


FIG.  10. — A,  ventral,  and  B,  lateral,  view  of  a  portion  of  the  cord  from  the 
cervical  region,     i,  ventral  median,  and  2,  dorsal  median,  fissures;  5,  ventral 
fibres  leaving  the  cord;  6,  dorsal  fibres  entering  the  cord;  61,  spinal  ganglion; 
7,  spinal  nerve  after  the  union  of  the  dorsal  and  ventral  fibres. 
(From  Ladd  and  Woodworth,  after  Schwalbe.) 

The  Autonomic  Nervous  System. — Besides  the  cerebro- 
spinal  nervous  system  there  is  another  relatively  independent 
nervous  system  known  as  the  autonomic  neroous  system.  This 
is  composed  of  a  double  chain  of  nerve-ganglia  and  nerve-fibres 
extending  on  both  sides  of  the  vertebral  column  from  the 
base  of  the  skull  downward  to  the  end  of  the  column.  In 
addition  there  are  nerve-ganglia  in  the  thoracic,  abdominal, 
and  pelvic  cavities;  also  isolated  ganglia  located  in  the  heart, 
in  the  walls  of  the  arteries,  and  in  the  eye-cavities.  While  the 
autonomic  system  is  connected  with  the  cere.bro-spinal 

~ 


PSYCHOLOGY 


^'Dendrites 


^Collaterals 


-Axon 


FIG.  ii. — Nerve-cell  from  the 
cerebral  cortex. 


vous  system,  it  is  a  relatively 
independent  and  self-directing 
system.  It  is  due  to  its  action 
that  the  vital  and  automatic 
processes  of  respiration,  circula- 
tion, digestion,  and  the  glandular 
processes  are  carried  on  without 
burdening  the  central  nervous 
system. 

Nerve-Cells . — The  nervous 
system  is  composed  of  millions 
of  nerve-cells  too  small  to  be 
seen  except  by  the  aid  of  a  power- 
ful microscope.  The  nerve-cell 
is  composed  of  a  protoplasmic 
cell-body  and  its  prolongations  or 
fibres.  These  prolongations  are 
of  two  kinds:  axons  and  den- 
drites.  The  whole  nerve-cell  (cell- 
body,  axon,  and  dendrites)  constitutes  a  nervous  unit  known 
as  the  neurone.  Each  cell-body  gives  off  many  dendrites, 
but  in  most  cases  only  a  sin- 
gle axon.  The  axon  is  smooth 
,  and  regular  in  contour  and 
I  preserves  the  same  diameter 
throughout  its  course.  It 
ends  in  a  brush  or  terminal 
jjberi«atkai^  In  some  cases 
it  gives  off,  along  its  course, 
branches  or  collaterals,  and 
these  end  also  in  terminal 
arborizations.  Axoss — ^ajy 
greatly  in  length.  While 
those"  wHcTrierminalie  within 
the  brain  are  short,  those 
which  lead  to  outlying  parts 


Dendrites 


FIG.  12. — Multipolar  nerve-cell  from 
the  cerebral  cortex.  In  a  cell  of 
this  type  the  axon  is  short  and  has 
many  branches. 


l.  PD 


FIG.  13. — A  section  through  the  brain  cortex.     Greatly  magnified. 
(From  Tborndike's  "Elements  of -Psychology,"  after  Kolliker.) 


34 


PSYCHOLOGY 


may  be  half  the  length  of  the  body.  The  true  nerve  sub- 
stance of  the  axon  (the  axis  cylinder)  is  protected  by  a 
medullary  sheath  which  disappears  near  the  cell-body  and  at 

I 


FIG.  14. — Nerve-cell  showing  fibrils. 
(From  Ladd  and  Wood  worth,  after 
Bethe.)  a,  b,  c,  d,  the  stumps  of 
several  dendrites;  Ax,  stump  of 
the  axon. 


FIG.  15. — Short  pieces  of  two  nerve- 
fibres.  (From  Ladd  and  Woodworth, 
after  Schafer.)  The  axis  cylinder 
appears  gray;  the  myelin  sheath  is 
stained  black;  the  primitive  sheath  ap- 
pears white.  R,  node  of  Ranvier;  c, 
the  nucleus  of  one  of  the  sheath-cells. 


the  terminals  of  the  axon.  Outside  the  medullary  sheath  is 
usually  found  a  thin  covering  known  as  the  nenrikmma. 
The  dendrites  are  rough  and  branch  more  gradually  from 


FIG.  16. — Motor-cell  from  the  ventral  horn  of  the  cord,  with  scheme  of  the 
course  of  its  axon.  (From  Ladd  and  Woodworth,  after  Barker.)  n,  the 
nucleus,  with  n1,  nucleolus;  d,  dendrites,  only  the  stumps  of  which  are 
shown;  a.h.,  hillock  from  which  the  axon  arises;  at  m,  the  axon  becomes 
invested  with  the  myelin  sheath;  n.R.,  a  node  with  branching  of  the  axon; 
m1,  a  muscle  in  which  the  axon  terminates  in  tel.,  the  motor  end-plate. 


30  PSYCHOLOGY 

each  other,  giving  off  antler-like^processes.  The  size  of  the 
dendritic  processes  becomes  rapidly  smaller  as  they  leave 
the  cell-body.  The  nerve-cells  are  supported  and  held  in 
place  by  nguroglia^cells  whose  numerous  processes  form  a 
frame  work  in  which  the  true  nerve-cells  rest. 


Dendrites 


FIG.  17. — Diagram  showing  the  probable  way  in  which  neurones  are  connected. 

The  function  of  the  cell-body  seems  to  be  that  of  rein- 
forcing and  inhibiting  the  nerve-impulses  which  pass  through 
them.  The  Hpprlritpg  raitY  the  impulses  to  the  cell-body  and 
the  axon  transmits  the  impulse  away  from  the  cell-body — to 
the  dendrites  of  other  neurones  or  to  the  glands  and  muscles 
of  the  body.  There  is  one  exception  to  this  rule.  The  fibres 
which  parry  sensory  impulses  from  the  different  sense-prgans 
to  the  cell-bodies  in  the  spinal  ganglia  resemble  axons  in 
structure! 

How  the  nervous  impulse  is  transmitted  from  one  neurone 
to  another  is  not  definitely  known.  Many  investigators  be- 
lieve that  each  neurone  is  a  distinct  individual  unit,  and  that 
where  neurones  form  a  functional  chain,  the  axonic  terminals 
of  one  neurone  merely  approach  the  dendrites  or  cell-body 
of  the  next  neurone.  These  points  of  contact  or  contiguity 


THE   NERVOUS   SYSTEM 


37 


between  neurones  over  which  the  nerve-impulse  is  passed 
from  one  to  the  other  are  called  svnabses.  Since  the  axons 
and  dendrites  have  many  branches,  the  terminations  of  one 


'larke's  column 
Spinal     End  organ  in 
Ganglion  /    Muscle 

*    '•     "*•        *     J*          -•   T-I      J 

End  organ 
in  Skin 


Cord 


Muscle 


Motor  neurones  in 
Ventral  horns 

FIG.  18. — Diagram  of  some  of  the  connections  between  sense-organs  and 
muscles  through  the  cord  and  brain. 

The  student  should  understand  that  this  diagram  is  far  too  simple  to  represent  all  the  facts  of 
nerve-connections. 

axon  may  connect  with  the  dendrites  of  a  number  of  other 
neurones.  Thus  an  impulse  may  spread  to  large  areas  of 
the  brain  and  under  different  conditions  take  different  path- 


38  PSYCHOLOGY 

ways  through  the  cord  and  brain.  A  single  fibre  from  the 
0* .  spinal  ganglion  makes  connections  with  fifty  or  sixty  differ- 
ent neurones  in  the  gray  matter  of  the  cord. 

Nature  of  the  Nervous  Impulse. — Just  what  the  nature 
of  the  nervous  impulse  is  we  are  not  able  to  say.  The  most 
popular  theory  regards  it  as  a  form  of  chemical  activity 
analogous  to  the  action  in  a  train  of  gunpowder,  which  when 
lighted  at  one  end  transmits  the  combustion  throughout  its 
entire  course.  It  has  been  suggested,  also,  that  the  nervous 
impulse  is  electrical  in  nature.  But  the  rate  of  nerve  trans- 
mission (not  more  than  300  feet  per  second)  is  much  too  slow 
for  that  of  any  known  electrical  action. 

Kinds  of  Neurones. — Neurones  may  be  classified  accord- 
ing to  their  function  into  (i)  sensory  or  afferent  neurones, 
(2)  motor  or  efferent  neurones,  and  (3)  associational  or  central 
-^neurones.  The  sensory  neurones  receive  stimulation  from  the 
outside  world  and  conduct  sense-impulses  to  the  sensory 
centres  of  the  brain.  The  motor  neurones  project  impulses 
outward  from  the  brain  to  the  muscles  and  glands.  The  cen- 
tral neurones  form  chains  for  connecting  the  different  parts 
of  the  brain,  as  for  instance  from  the  sensory  to  the  motor 
areas.  When  neurones  pass  from  one-half  of  the  brain  or 
cord  to  the  other  half  they  are  spoken  of  as  commissural 
neurones. 

The  cell-bodies  of  the  central  and  motor  neurones  lie 
within  the  brain  and  spinal  cord,  while  the  cell-bodies  of  the 
sensory  neurones  are  found  near  the  sense-organs  or-  in  the 
spinal  ganglia  outside  the  brain  and  cord.  ^  When  a  large 
number  of  cell-bodies  are  grouped  closely  together  the  group 
is  spoken  of  as  a  ganglion. 

The  separate  nerve-fibres  are  (except  at  their  terminals) 
bound  together  in  bundles  or  nerves.  They  are  referred  to 
as  medullated  and  non-medullated  nerves,  according  as  the 
^ fibres  which  compose  them  are  medullated  or  non-medullated. 

White  and  Gray  Matter. — The  white  matter  of  the  brain, 
cord,  and  nerves  is  made  up  of  medullated  nerve-fibres.  It  is 


THE  NERVOUS   SYSTEM 


39 


the  medullary  sheath  which  gives  the  whitish  appearance. 
The  gray  matter  is  the  true  nerve  substance  and  is  found  in 
the  cell-bodies  and  in  the  fibres.  In  the  medullated  fibres 
the  true  nerve  substance  is  hidden  from  view.  The  gray  sub- 
stance comprises  the  cortex  or  outer  layer  of  the  brain,  cer-( 
tain  ganglia  within  the  brain, 
and  the  central_core  of  the 
spinal  cord.  The  entire  outer 
surface  of  the  brain  is  cov- 
ered with  a  layer  of  gray 
matter  (cell-bodies  and  un- 
medullated  fibres)  properly 
protected  from  the  bony  tis- 
sue of  the  skull  by  three 
membranes- — the  dura  mater, 
the  arachnoid,  and  the  pia 
mater.  The  corpora  striata, 
thalami,  corpora  quadrigem-  FIG.  19— Frontal  section  through  the 


ina   are   also  composed  of 
masses  of  gray  matter.     In 


ganglia  (gray  matter).  The  light  portions  rep- 
resent the  mass  of  medullated  fibres  within 
the  brain  (white  matter). 


cerebral  hemispheres. 
(From  Ladd  and  Woodworth,  after  Gegenbaur.) 

the  medulla  and  other  parts    The  shaded  ^^  repr^  -the  co^tex  and 
are  found  smaller  masses  of 
gray    matter    called    nuclei. 

The  white  matter  of  the  brain  is  made  up  of  the  bands 
and  bundles  of  medullated  nerve-fibres  connecting  the  cortex 
and  the  lower  brain  ganglia.  The  white  matter  in  the  cord 
(the  outer  layers)  is  made  up  of  medullated  fibres  passing 
to  and  from  the  brain. 

The  true  nerve  substance  possesses  two  chief  character- 
istics— irritability  and  conductivity.     By  irritability  is  meant/ 
the  capacity  to  respond  to  stimulation  by  some  kind  of  nerve  { 
process,  and  by  conductivity  the  capacity  to  pass  the  nerve      « 
impulse  from  one  point  to  another.     The  impulse  is  carried    A 
from  dendrites  to  axon   through  the  cell-body.     The  cell- 
body  possesses  the^  power  to  npdifytheimr^&es^By^rein- 
forcing  or  inhibiting  them.     The  direcTionwmch  an  impulse 


PSYCHOLOGY 


/ 


D 


takes  through  the  brain  is  determined  by  the  condition  of 
the  synapses  at  the  moment,  and  this  is  determined  by  the 
modifications  of  the  brain  tissue  handed  down  through  hered- 
ity and  by  those  made  by  the  past  experiences  of  the  organism. 
The  Fibre  Connections  of  the  Brain. — The  medullated 

fibres  which  consti- 
tute the  great  nerve 
tracts  of  the  brain 
and  cord  may  be  con- 
sidered under  three 
groups:  (i)  Projec- 
tion fibres,  (2)  associ- 
ation fibres,  (3)  com- 
'M  missural  fibres. 

(i)  The  projection 
fibres  join  tjie_cixrlex 
withthe  rest^of  tfcf 
bnun__aacL_jaath-  the 
spinal  cord.  These 
fibres  bring  in  im- 
pulses from  the  sense- 
organs  and  send  out 
impulses  to  the  mus- 
cles. Those  that 
bring  in  the  sensory 
impulses  are  called 

the  asfending^fibres,  while  those  that  send  out  the  motor 
impulses  are  called  the  descending  fibres . 

The  descending  fibres  are  axons  from  the  motor  neurones 
in  the  cerebral  cortex.  Of  these  fibres  those  which  go  to  the 
nuclei  of  the  cerebral  nerves  are  known  as  genjsulate  fibres. 
As  they  pass  downward  into  the  lower  brain  they  cross  over 
to  the  opposite  side,  and  there  in  the  nuclei  of  the  motor 
cerebral  nerves  communicate  with  the  neurones  which  go  to 
the  muscles  of  the  head  and  neck.  The  other  descending 
fibres  from  the  cerebral  cortex  communicate  with  the  motor 


FIG.  20. — Diagrammatic  cross-section  through 
the  cord  showing  gray  and  white  matter. 
WW,  white  matter  or  medullated  fibres; 
GG,  gray  matter;  A,  afferent  sensory  fibres 
passing  through  S.  G.,  the  spinal  ganglion, 
into  the  posterior  horn  of  the  gray  matter; 
E,  efferent  motor  fibres,  most  of  which  lead 
to  muscles  like  M,  many  of  which  connect 
with  the  sympathetic  ganglia,  like  Sy;  C, 
central  cell,  probably  traversed  as  a  rule  by 
impulses  passing  from  A  to  E;  DP,  dorsal, 
or  posterior,  surface  of  cord;  VA,  ventral, 
or  anterior,  surface. 

(From  Angell's  "Psychology.") 


HE   NERVOUS   SYSTEM 


-Crossing  of  motor 
fibres 

Crossed  pyramidal 

fibres 

— 'Direct  pyramidal 
fibres 


Motor  fibres  from 

anterior  horn 

of  cord 


FIG.  21. — The  motor  tract. 


neurones  in  the  anterior  horns  of  the  spinal  cord.  They  are 
known  as  the  pyramidal  fibres.  From  the  cerebral  cortex 
they  pass  down  through  the  internal  capsule  to  the  pyramids 


PSYCHOLOGY 


-  Nucleus  cuneatus 
"  Nucleus  gracilis 


I  Sensory  fibres 
|  of  posterior 
[  nerve  roots 


FIG.   22. — The  sensory  tract. 

of  the  medulla.  Here  the  larger  part  of  the  pyramidal 
fibres  cross  to  the  opposite  side  and  descend  in  the  lateral 
column  of  the  cord  as  the  crossed  pyramidal  tract.  In  each 


THE  NERVOUS   SYSTEM  43 

segment  of  the  cord  pyramidal  fibres  enter  the  gray  matter 
of  the  cord  and  communicate  with  the  motor  neurones  in  the 
anterior  horn,  where  originate  the  motor  nerves  which  go  to 
the  muscles  of  the  body.  Some  of  the  pyramidal  fibres, 
forming  the  direct  pyramidal  tract,  pass  downward  in  the 
anterior  column  without  crossing.  These  fibres,  however, 
finally  cross  to  the  opposite  side  of  the  cord  at  lower  levels, 
and  in  each  case  they  communicate,  as  do  the  crossed  pyram- 
idal fibres,  with  the  motor  neurones  in  the  anterior  horn. 
Thus  it  is  seen  that  each  cerebral  hemisphere  controls  the 
muscles  on  the  opposite  side  of  the  body.  Beside  the  fibres 
already  described,  other  descending  fibres  run  from  the  cere- 
brum to  the  cerebellum,  which  in  turn  sends  fibres  to  the 
lateral  and  anterior  columns  of  the  cord. 

The  ascending  projection  fibres  form  the  sensory  tracts 
leading  from  the  ganglia  of  the  cerebral  and  spinal  nerves. 
Nearly  all  _t VIP  spnsnry  fibres  of  the  cerebral  nerves  p^o  to  the 
sensory  nuclei  in  the  medulla  and  pons.  From -these  nuclei 
axons  cross  to  the  opposite  side  and  communicate  with  the 
thalamus.  From  here  other  fibres  send  on  the  sensory  im- 
pulses to  the  various  parts  of  the  cortex.  In  a  similar  man- 
ner the  sensory  fibres  from  the  spinal  nerves  go  from  the 
spinal  ganglia  through  the  cord  to  nuclei  in  the  medulla. 
From  there  new  axons1  cross  to  the  opposite  side  and  pass 
through  the  mesial  fillet  to  the  thalamus  and  mid-brain,  and 
thence  to  the  cerebral  cortex.1  Thus  impulses  from  the 


al 
\ri 


sense-organs  from  oneeide  of  the  body  are  sent  through  a 


chain  of  neurones  to  th 


Beside  the  nerves  which  connect  the  sense-organs  with  the 


cerebrum  there  are  oth 
the  cord  and  medulla  t 
bellum  to  the  cerebral  h 


cortex  of  the  opposite  hemisphere. 


r  projection  fibres  which  pass  from 
the  cerebellum,  and  from  the  cere- 
jmisphere. 


1  There  are  exceptions  to  mis  general  rule.  Many  fibres  from  the  sense- 
organs  in  the  skin  cross  in  the  cord  and  pass  upward  in  the  opposite  side  of 
the  cord.  Some  of  the  fibres  from  the  sense-organs  in  the  muscles  pass  upward 
in  the  same  side  of  the  cord  apd  go  to  the  cerebellum  without  crossing. 


44 


PSYCHOLOGY 


The  fibres  of  the  optic  nerves  follow  a  somewhat  different 
course  from  that  of  the  other  cerebral  nerves.  The  fibres 
from  the  inner  or  nasal  half  of  each  eye  cross  in  the  optic 


Occipital  lobe 

)ptic  radiation 
Superior  colliculus 


Lateral  or  external 
gcniculate. 

Optic  thalamus 


FIG.  2$. — Scheme  showing  the  distribution  of  the  optic  fibres. 
(From  Howell's  "Text-Book  of  Physiology.") 

chiasma  and  go  to  the  opposite  side  of  the  brain,  while  the 
fibres  in  the  outer  or  temporal  half  of  each  eye  go  to  the 
same  side  of  the  brain.  These  fibres  from  the  retinae  end  in 
the  region  of  the  thalami  and  upper  quadrigeminal  bodies. 
This  region  constitutes  the  lower  visual  centres.  From  here 
new  fibres  continue  to  the  occipital  lobes  of  the  cortex  and 
end  there  in  the  higher  visual  centres. 


,  Cerebrum 


Superior 
Corp.  Quad. 


Cochlea 


Semicircular 
Canals 

FIG.  24.  —  Scheme  showing  the  distribution  of  the  cochlear  fibres. 


Nuclei  of 
Motor  Cerebral 
Nerves 


Fibres  to 
Cord 


^/Cochlea 


y 

Semicircular 
Canals 

FIG.  25. — Scheme  showing  the  distribution  of  the  vestibular  fibres. 


46  PSYCHOLOGY 

The  auditory  nerve  contains  fibres  from  two  different 
parts  of  the  ear — the  cochlea  and  the  semicircular  canals. 
The  cochlear  fibres  go  to  the  temporal  lobes  of  the  cerebrum, 
while  the  fibres  from  the  semicircular  canals  go  to  the  cere- 
bellum. 


FIG.   26. — Cut  showing  the  association  fibres  joining  the  different    cortical 

centres  with  one  another. 
(From  Ladd  and  Woodworth,  after  Starr.) 

(2)  The  association  fibres  form  the  nerve  pathways  which 
connect  the  different  parts  of  the  same  cerebral  hemisphere1 
with  each  other.  The  sensory  impulses  which  are  projected 
from  the  sense-organs  to  the  various  sensory  centres  within 
the  brain  are  reflected,  or  projected,  back  to  the  muscles  from 
the  motor  centres,  and  find  expression  in  movements.  Now 
the  connection  between  the  different  sensory  centres  and 
between  the  sensory  centres  and  the  motor  centres  are  made 
by  the  association  fibres.  By  means  of  short  and  long  fibres 
both  adjacent  and  remote  areas  of  the  cortex  are  connected 
with  each  other.  The  higher  processes  of  consciousness — 
perception,  imagination,  memory,  thought,  etc. — demand  the 

1  Or  the  cerebellar  hemisphere. 


THE   NERVOUS   SYSTEM 


47 


co-operation  of  the  various  sensory  areas  and  depend,  there- 
fore, upon  the  associative  connections  between  them. 

Complex  forms  of  conscious  behavior  also  depend  upon 
the  co-operation  of  different  parts  of  the  cortical  areas. 

(3)  The  commissural 
fibres  are  found  in  all  parts 
of  the  central  nervous  sys- 
tem. They  are  the  fibres 


which   connect 


hemi- 


FIG. 27. — A  transverse  section  through 
the    two    hemispheres    showing    com- 
missural  fibres   connecting   the  hemi- 
spheres. 
(From  Judd's  "Psychology,"  after  Edinger.) 


sphere  of  the  brajn^and 
cord  with  the  Bother.  In 
the  cerebrum  the  most 
prominent  commissural 
pathways  are  formed  by 
the  corpus  callosum  and 
the  anterior  commissure. 
The  fibres  of  the  corpus 
callosum  join  the  cortex  of 
one  side  with  that  of  the 
other.  The  fibres  of  the 
anterior  commissure  con- 
nect the  temporal  lobes  of  opposite  sides. 

Localization  of  Function.  —  With  regard  to  function  the 
subdivisions  of  the  brain  may  be  classed  under  two  headings, 
the  higher  centres  and  the  lower  centres.  The  higher  centres 
are  located  in  the  cortex  of  the  cerebral  hemispheres.  These 
centres  constitute  the  neural  basis  for  the  intellectual  proc- 
esses. The  lower^centres  are  found  between  the  cerebral 
cortex  and  the  cord  and  include  the  thalami,  the  corpora 
quadrigemina.  the  medulla  oblongata.  the  polTs,  tile"  CraHm.1 
ganglia,  and  the  cerebellum.  The  lower  centres  control, 
more  or  less  independently  of  the  higher  conscious  processes, 
the  vital  or  vegetative  prnr^sesuof  the  body. 

The  area  of  general  sensations  —  pressure,  pain,  and  tem- 
perature sensations  —  occupies  the  convolution  just  pos- 
terior to  the  fissure  of  Rolando.  The  kinaesthetic  sensa- 


48  PSYCHOLOGY 

tions,  or  sensations  of  movement,  also  have  their  seat  in 
this  region. 

The  auditory  area  is  located  in  the  superior  convolution  of 
the  temporal  lobe. 

The  visual  area  is  found  in  the  cuneus  and  gyrus  lingualis. 

The  olfactory  area  is  situated  in  the  forward  part  of  the 
hippocampal  convolution. 

The  gustatory  area  has  not  been  definitely  located,  but  is 
supposed  to  be  situated  in  the  hippocampal  convolution  just 
behind  the  olfactory  area. 

The  areas  which  immediately  surround,  or  lie  adjacent  to, 
the  sensory  areas  proper,  are  supposed  to  be  sensory  psychic 
areas,  or  the  areas  involved  in_the 


prehension  of  the  sensations  themselves.  For  instance, 
merely  to  hear  a  sound  is  one  phase  of  the  experience.  To 
understand  the  sound  ^  the  gnnnrl  nf  a  b^1^  or  of  a  passing 
treet-car,  is  another  phase  of  the  experience.  The  psychic 
areas  are_responsible  for  this  latter  function.  Injury  to  these 
areas  may  leave  the  individual  able  to  hear,  or  see,  or  taste, 
etc.,  without  being  able  to  understand  the  nature  of  the 
sensations. 

The  motor  area  lies  just  in  front  of  the  fissure  of  Rolando 
in  the  precentral  convolution  and  extends  into  the  superior, 
middle,  and  inferior  convolutions  of  the  frontal  lobe,  and 
into  the  mesial  surface  of  the  hemisphere.  The  motor  area 
may  be  divided  into  upper,  middle,  and  lower  regions.  The 
muscles  of  the  face,  tongue,  and  larynx  are  controlled  by  the 
lower  region;  the  muscles  of  the  shoulders,  arms,  hands,  and 
fingers  are  controlled  by  the  middle  region;  the  muscles  of 
the  trunk,  legs,  and  feet  are  controlled  by  the  upper  region. 
In  most  cases  the  motor  centres  of  one  hemisphere  control 
the  muscles  of  the  opposite  side  of  the  body.  This  is  not, 
however,  universally  true.  Certain  muscles  of  the  face,  the 
A%/  muscles  of  mastication,  and  those  of  the  pharynx  and  larynx 
yeceive  motor  fibres  from  both  hemispheres.  The  fact  that 
destruction  of  the  motor  centres  in  one  hemisphere  is  not 


Fissure  of  Rolando 


'edulla 
Cord 

FIG.  28. — Areas  of  localization  on  the  lateral  surface  of  the  hemisphere. 
Motor  area  in  red;  bodily  sense  area  in  blue;  auditory  area  in  green; 
visual  area  in  yellow. 


ftifpocampal 
Convolution 


Cerebellum, 

•Medulla 
Cord 

FIG.  29. — Areas  of  localization  on  the  mesial  surface  of  the  hemisphere. 
Motor  area  in  red;  bodily  sense  area  in  blue;  visual  area  in  yellow;  olfac- 
tory and  gustatory  areas  in  purple. 


THE   NERVOUS    SYSTEM 


49 


followed  by  complete  paralysis  of  the  muscles  on  the  opposite 
side,  indicates  that  these  muscles  are  partially  controlled  by 
the  motor  centres  of  the  other  hemisphere. 

The  association  areas  occupy  portions  of  the  cerebral  hemi- 
spheres not  taken  up  by  the  sensory  and  motor  areas.     Three 


FIG.  30. — Diagram  showing  the  chief  regions  of  the  motor  and  sensory  centres. 

large  areas  may  be  designated  as  association  areas:  the  an- 
terior associational  area  occupies  the  fore  part  of  the  frontal 
lobe;  the  middle  associational  area  occupies  the  Island  of  Reil; 
the  posterior  associational  area  occupies  a  large  part  of  the 
occipital  and  temporal  lobes  and  practically  all  of  the  parietal 
lobe.  These  areas  are  supposed  to  be  the  centres  for  the 
higher  conscious  processes — the  intellectual  centres,  so  to 
speak.  It  is  here  that  the  various  sensory  experiences  are 
co-ordinated  and  elaborated  into  processes  of  knowledge  and 
thought.  These  centres  are  often  referred  to  as  the  Flechsig 
areas  from  the  fact  that  Flechsig  first  pm'nfpr]  ^^  ffr^-  fEZ 
myelination  or  development  of  the  medullary  sheath  of  <  the 
nerve-nbres  to"  these  areas  takes  place  only  after  the  myelina- 


'' 


5°  ^  7  PSYCHOLOGY 


tion  of  the  nerve  tracts  to  and  from  the  sensory  and  motor 
centres  has  taken  place.  At  birth,  according  to  Flechsig,  all 
the  sensory  fibres  of  the  lower  parts  of  the  brain  are  devel- 
oped, but  only  two  tracts  —  the  olfactory  amLtbfi  giista.t.nry  — 
are_developed  within  the  cerebrum.  Gradually,  however,  the 
tactual,  visual^andjmditorv  tracts  become  myelmatecj^and 
readyl:o  function.  The  tracts  from  the  various  sensory  cen- 
tres to  the  association  areas  are  the  last  to  develop.  Upon 
this  fact,  together  with  the  supposed  fact  that  the  cellular 
itructure  within  the  association  areas  is  uniform  and  differ- 
nt  from  that  in  the  sensory  and  motor  areas,  he  based  his 
eory  that  the  association  centres  are  the  higher  intellectual 
litres.  Later  investigators  have  demonstrated  that  not 
only  do  the  several  sensory  and  motor  centres  show  a  differ- 
ent cellular  structure,  but  the  various  parts  of  thf*  flsgnri'atif>n 
centres  also  show  differentiation  i™,  thig  ™*spprf  If  each 
specific  lorm  of  cell-structure  of  the  cortical  areas  corresponds 
to  a  particular  mental  function,  the  association  areas  will 
some  day  be  mapped  out  to  indicate  the  localization  of  the 
different  intellectual  functions.  At  present,  however,  we 
know  very  little  about  the  function  of  these  large  association 
areas.  There  is  sufficient  evidence  to  establish  the  fact  that 
/certain  parts  of  these  areas  lying  adjacent  to  the  sensory 
Ncentres  serve  as  memory  areas  for  these  centres.  For  in- 
stance, clinical  cases  have  been  reported  in  which  loss  of 
ability  to  recognize  objects  seen,  or  held  in  the  hand,  or  heard, 
follows  a  lesion  in  the  brain  areas  in  the  immediate  vicinity 
of  the  visual,  tactual,  or  auditory  sense  areas  respectively. 
In  such  cases  the  patient  can  see  and  feel  and  hear  the  ob- 
jects, but  memory  for  the  sensory  experiences  is  lost.  On 
the  other  hand,  while  destruction  of  the  sense  centres  alone  is 
followed  by  blindness,  deafness,  etc.,  memory  for  the  sensa- 
tion sjgreiveri  bpfnr"  thffl  injury  i*  fifi'H  intact. 

The  motor  speech  centre  lies  in  the  inferior  frontal  convo- 
lution in  the  left  cerebral  cortex.  Injury  to  this  centre 
(Breed's  Centre)  is  followed  by  the  loss  of  the  ability  to 


THE  NERVOUS   SYSTEM  51 

speak  properly.  This  condition  is  known  as  motor  aphasia. 
Broca's  convolution  is  evidently  not  the  centre  for  the  mus- 
cles  of  speech;  for  in  cases  of  motor  aphasia  the  patient  is 
still  able  to  pronounce  words..  The  words  do  not,  however, 
form  sentences  or  express  meaning,  but  are  hopelessly  mixed. 

The  sensory  speech  centre  also  is  found  on  the  left  side  in 
the  posterior  part  of  the  superior  temporal  convolution  and 
in  the  adjoining  part  of  the  superior  marginal  convolution 
(Wernicke's  Centre).  Injury  to  this  centre  is  followed  by  the 
loss  of  the  ability  to  understand  spoken  words.  The  patient 
is  still  able  to  hear  words,  Jnit  he  fails  to  comprehend  them. 
This  condition  is  known  as  word-deafness  or  sensory  a-bha^ia. 

The  visual  centre  for  written  language  lies  just  posterior  to 
Wernicke's  Centre  in  the  angular  convolution.  Injury  to 
this  centre  is  followed  by  the  loss  of  the  ability  to  recognize 
or  understand  printed  or  written  characters.  The  patient  is 
able  to  see  the  characters,  but  they  mean  nothing  to  him. 
This  condition  is  known  as  word-blindness,  OT^alexia^ 

The  speech  centres  seem,  therefore,  to  be  psychic  centres 
within  which  images  of  the  movements  of  articulation,  of  the 
sound  of  words,  and  of  the  visual  forms  of  written  characters 
are  aroused.  When  such  mental  representation  is  made  im- 
possible by  brain  lesions,  aphasia,  or  the  inability  to  use  or 
understand  words,  results. 

It  has  been  claimed  by  some  authorities  that  the  language    ^ 
centres  in  left-handed  persons  are  located  on  the  right  side     • 
of  the  brain,  but  this  claim  has  been  denied  by  other  investi- 
gators. 

The  two  halves  of  the  brain  are  no^.  identical  in  function. 
Not  only  is  speech  a  one-sided  function,  but  many  consecu- 
tive and  skilled  movements  of  the  hands  and  fingers  are  con- 
trolled by  one  side  of  the  cerebral  cortex,  usually  the  left 
hemisphere.  In  many  cases  of  lesions  of  the  left  hemisphere, 
followed  by  paralysis  of  the  right  hand,  there  is  also  a  serious 
impairment  of  the  ability  of  the  left  hand  to  execute  move- 
ments. Cases  have  been  reported  in  which  lesions  in  the 


52  PSYCHOLOGY 

corpus  callosum,  the  band  of  fibres  which  connects  the  two 
hemispheres,  are  followed  by  a  lessening  of  the  ability  to 
use  the  left  hand,  a  result  due,  without  doubt,  to  the  fact 
that  the  conscious  factors  involved  are  conditioned  by  the 
left  cortex.  It  would  seem,  therefore,  that  the  images  neces- 
sary for  the  conscious  control  and  execution  of  certain  ac- 
quired movements  depend  very  largely  upon  the  activity  of 
the  left  cerebral  cortex. 

The  higher  complex  intellectual  processes  are  probably 
not  located  in  any  single  cortical  area,  but  depend  upon  the 
co-ordinated  activity  of  many,  if  not  all,  of  the  cerebral  areas. 


$i^ 


6\Jts~^>w 

.  f^J 


** 

f. 


a+*~»-*+~i 
(*tl 

*9  HT* 


is^rvww1 


(  pa 


TTT 
f-' 

ATTENTION 


If  we  examine  our  consciousness  at  any  moment  we  findi  ^r 
that  a  part  of  its  content  stands  out  in  bold  relief  from  the! 
rest  —  that  we  are  mentally  occupied  with  some  'one  presenta- 
tion of  the  senses,  or  engaged  in  the  elaboration  of  some' 
thought  or  idea,  at  the  expense  of  other  possible  presentations 
or  ideas.  In  other  words,  we  find  that  some  part  of  t>he  con- 
tent is  clearer  and  more  definitely  in  consciousness  than  the 
rest  of  it.  If  our  eyes  rest  upon  a  landscape,  some  one  object 
momentarily  occupies  the  centre  of  our  awareness.  If  we 
listen  to  the  sounds  of  the  street,  some  one  sound  is  clear  and 
distinct,  or  at  least  clearer  and  more  distinctly  apprehended 
than  the  other  sounds  of  which  we  are  conscious.  If  we  are 
absorbed  in  meditation,  some  one  idea  is  uppermost  in  our 
thinking.  We  further  observe  that  there  is  a  constant  shift-  ( 

ing  of  the  elements  of  the  total  content.  Now  one  and  now  T 
another  part  of  the  content  becomes  clear  and  definite,  and  ^  / 
then  fades  to  give  place  to  its  successor.  There  is  a  constant 
change  from  clearness  to  obscureness  and  from  obscureness 
to  clearness.  We  also  find  that,  at  any  one  time,  although 
there  are  a  number  of  different  objects  appealing  to  the 
senses,  or  different  ideas  that  might  be  entertained  in  the 
mind,  yet  it  is  always  one  of  them,  or  a  single  group  of  them, 
that  occupies  the  centre  of  the  stage.  Another  fact  we  notice 
is  that  the  changes  in  the  content  take  place  in  a  definite 
order,  either  in  accord  with  some  inner  plan  of  action  or 
thinking,  or  in  conformity  to  the  order  of  presentation  of 
outer  objects.  We,  shall  see  in  a  later  chapter  that  the  rise 
and  fall  of  ideas  in  the  clearest  part  of  consciousness  takes 
place  according  to  a  general  law  —  the  law  of  association. 

S3 


¥ 


I 


54  PSYCHOLOGY 

For  instance,  if  at  this  moment  I  am  thinking  of  Harvard 
University,  the  next  clear  thought  that  domes  into  my  mind 
is  that  of  Professor  James.  This  is  because  of  the  past  asso- 
ciation of  these  two  thoughts  in  my  experience. 

We  also  notice  that  these  changes  in  the  nature  of  con- 
v  sciousness  are  accompanied  by  impulses  to  movements  in  the 
M  various  parts  of  the  organism;  especially  in  the  muscles  of 
.  •accommodation  of  the  sense-organs.  The  eyes  are  adjusted 
^4  in  seeing.  The  head  is  turned  in  hearing.  Movements  of 
N  inhalation  are  made  in  smelling.  These  movements  serve  to 
make  the  stimulus  in  each  case  more  effective.  Besides  the 
movements  of  sense-accommodation,  other  movements  of  the 
body  can  be  detected.  Facial  expressions  and  bodily  atti- 
tudes conform  to  the  changes  of  thought.  The  wrinkled  brow 
and  the  constrained  attitude  are  usually  present  in  deep 
thought.  The  smile  and  the  frown  each  correspond  to  defi- 
nite qualities  of  consciousness.  Changes  in  heart  action  and 
respiration  parallel  the  changes  in  mental  activity.  So  we 
can  say  that  wherever  consciousness  changes  its  direction, 
there  we  may  find  impulses  to  movement. 

As  a  result  of  movements  of  accommodation  in  the  sense- 
organs  and  expressions  in  other  parts  of  the  body  during  the 
activity  of  consciousness,  there  arises  a  complex  of  sensations 
which  become  a  part  of  the  content  of  experience.  This  com- 
plex is  made  up  of  sensations  of  strain  and  effort  in  the  various 
muscles.  When  we  listen  for  a  certain  sound  we  distinctly 
feel  the  tension  of  the  muscles  of  the  neck  and  the  faint  sen- 
sations in  the  muscles  of  the  middle  ear.  When  we  look  for 
a  certain  object  in  a  scene  before  us  we  feel  quite  as  dis- 
tinctly the  movements  of  the  eyes.  When  we  try  to  remem- 
ber or  solve  a  difficult  problem  we  feel  the  sensations  of 
strain  in  the  muscles  of  the  forehead.  All  these  sensations 
are  designated  by  the  term  kinaesthetic  sensations — sensations 
of  movement. 

Lastly  we  notice  that  the  changes  in  consciousness  are 
often  co-ordinate  with  feeling.  The  ideas  and  thoughts  that 


ATTENTION  55 

come  clearly  into  our  minds,  and  find  lodgment  there,  are 
frequently  those  that  appeal  to  us — those  that  refer  to  things 
we  like  or  those  that  are^useful  in  avoiding  the  things  we  Dis- 
like. ^Ve  seek  the^leasant  and  avoid  thejmpleasaiit.  Con- 
sequently the  ideas  and  sensations  that  become  clear  and 
definite  are  those  that  possess  affective  qualities. 

Now,  in  our  examination  of  consciousness  we  have  noted 
the  following  characteristics: 

i .  Structure  into  clear  and  unclear  parts. 
.    2.  Change  of  content. 

3.  Selection  of  certain  parts  of  the  total  content. 

4.  Sensations  of  adjustment — kinaestheltic  sensations. 

5.  Affective  quality.  / 

These  are  the  characteristics  of  consciousness  which  make 
up  attention.  At  one  time  or  another  in  the  history  of  psy- 
chology each  of  these  characteristics  has  been  picked  out  and 
put  forward  as  the  fundamental  character  of  attention.V  ^ 
^This  accounts  for  the  various  definitions  and  points  of  view 
which  we  meet  in  the  literature  of  the  subject. 
*  If  now,  in  addition  to  the  content  which  we  discover  in 
tha  attention-consciousness,  we  assume  or  infer  a  subject  of 
Jnsciousness,  or  a  permanent  mind  back  of  the  content,  we 
ight  be  tempted,  like  some  of  the  older  psychologists,  tol/v/iS 
efine  attention,  as _the  power  of  the  mind  to  concentrate.  | 
change,  and  prolong  conscious  states.  But  by  so  doing  we 
run  iHtor~aT~ar/-(/e-7ac^f or  after  defining  attention  as  "the 
power  of  the  mind,"  et  cetera,  we  can  go  no  further  with  the 
definition,  because  we  know  nothing  about  this  mind,  or  ego, 
or  self  which  exerts  its  power  in  this  way.  We  cannot  find 
out  how  it  concentrates,  changes,  or  prolongs  conscious  states. 
We  gain  nothing  by  this  definition  of  attention  beyond  a  con- 
venient way  of  holding  the  facts  together  in  our  thinking. 
The  danger  of  such  a  conception  of  attention  lies  in  taking  it 
as  an  explanation  of  the  facts.  However,  it  is  a  convenient 
way  of  speaking  into  which  we  often  fall,  even  in  empirical 
psychology.  We  speak  of  "the  power  of  the  mind  to  con- 


56  PSYCHOLOGY 

centrate,"  "the  activity  of  the  mind  in  attending,"  or  use 
other  expressions  which  seem  to  infer  that  attention  is  some 
power  back  of  the  conscious  states.  If  we  understood  what 
was  said  in  the  introductory  chapter,  it  will  be  unnecessary 
when  we  use  such  expressions  to  stop  and  explain  that  we  are 
not  referring  to  a  metaphysical  entity  by  the  words  "mind" 
or  "self,"  or  that  we  look  upon  attention  as  something  other 
than  that  found  in  the  content  of  consciousness.  Itjsjtrue 
that  in^our  popular  thinking  the  clearness^the  changes,  the 
selection,  and  the  jmotor  impulses  of_  consciousstates  are 
looked  uponas  due  to  the  Jjgtivityof  so7rie^ge^t~wnTch_we 
Ijetieve  ^exists  ^benlnd  the  contents  of  consciousness.  But 
poputer-^tKougKt  is  saturated  with  uncritical  metaphysics. 
Our  business  is  first  to  consider  the  facts.  All  that  introspec- 
tion reveals  to  our  observation  in  attention  are  the  five  char- 
acteristics which  we  have  just  enumerated.  Of  these  charac- 
teristics of  attention  the  most  important  one — the  mark  by 
which  we  define  attention — is  clearness.  Clear  or  vivid  con- 
sciousness is  a  universal  characteristic  of  all  attention,  and 
unclear  consciousness  a  characteristic  of  non-attentive  con- 
sciousness. Several  ways  of  describing  the  structure  of  con- 
sciousness in  which  attention  appears  have  become  current 
in  psychology.  The  difference  between  attentive  conscious- 
ness and  non-attentive  consciousness  may  be  described  as 
one  of  degree  or  level.1  Attention  is  a  high-level,  while  non- 
attentive  consciousness  is  a  low-level  consciousness.  The  dif- 
ference between  the  levels  is,  of  course,  that  of  degree  in  the 
clearness  of  consciousness.  Whether  there  are  only  two  de- 
grees of  clearness,  or  several  degrees  or  levels,  cannot  be 
determined  at  the  present  time,  although  the  experimental 
evidence  favors  the  hypothesis  of  several  degrees,  which  shade 
off  from  the  highest  degree  of  close  or  rapt  attention  to  the 
lowest  degree  of  diffused  consciousness. 

Another  way  of  picturing  the  structure  of  consciousness 
is  illustrated  in  Figure  31.    Attention  would  then  be  the  cen- 

1  Titchener:  "  Textbook  of  Psychology,"  p.  276. 


ATTENTION 


57 


tral  circle,  while  the  degrees  of  diffused  or  vague  conscious- 
ness would  be  represented  by  a  series  of  widening  circles. 
The  central  circle  is  spoken  of  as  the  focusjrf  consciousness, 
and  the  outer  circles  as  the  fringe,  or  margmToL 

Sometimes  it  is  convenient  to 
speak  of  attention  as  the  fore- 
ground of  consciousness,  and  non- 
attentive  consciousness  as  the 
background.  The  foregroungL_is. 
clear  and  distinct,  while  the  back- 
ground  is  diffused  or  unclear. 

~XT1  these  pairs  of  terms — clear 
and  unclear,  high-level  and  low- 
level,  focus  and  margin,  foreground 
and  background  —  describe  the 
same  fact,  the  difference  in  struc- 
ture in  the  contents  of  conscious- 
ness at  any  one  moment.  The 
first  term  in  each  pair  refers  to  the 
wide-awake  and  effective  part  of 
the  conscious  field,  and  suggests 
that  attention  is  clear  and  central  consciousness. 

The  fact  that  attention  is  constantly  changing  its  direc-.K 
tion,  now  resting  upon  this  object,  and  now  upon  that,  is^jy 
another  characteristic  that  we  have  noted.     No  conscious 
state  remains  clear  or  focal  for  any  length  of  time.     This  has, 
gjven  ground  for  the  definition  of  attention  as  the  most  active 
part  of  consciousness,  and  has  introduced  the  idea  of  atten- 
tion asaprocess ,  or  an  activity,  a  functional  characteristic  as 
distinguished  from  the  structural  one  we  have  just  been  djfr- 
cussing.    And  then  the  further  observable  fact  that  atten-' 
tion  gives  itself  to  one  of  many  objects  presented  to  the 
senses,  or  to  one  of  many  possible  lines  of  thought,  adds 
another  characteristic   to   the   conception  of  attention  and 
gives  rise  to  the  definition  of  attention  as  selective  conscious- 
ness.    If  we  emphasize  the  fact  that  attention  involves  cer- 


FIG.  31. — Graphic  representa- 
tion of  the  field  of  conscious- 
ness: i,  attention,  or  the 
focus  of  consciousness;  2 
and  3,  fringes  of  diffused 
consciousness;  4, 
sciousness. 


subcon- 


/N 

:     f 


58  PSYCHOLOGY 

tain  adjustment  activities  which  turn  the  sense-organs  toward 
the  object  to  be  attended  to,  or  that  certain  movements  of 
j  the  body  are  made  anticipatory  to  ideas  we  entertain  in  atten- 
|  tive  thinking,  we  have  still  another  characteristic.  It  is  in 
this  case  rudimentary  will,  or  conation.  And  still  again,  if  we 
pick  out  the  sensations  of  strain  and  effort  in  these  move- 
ments of  accommodation  we  have  another  characteristic 
which  we  may  look  upon  as  the  chief  mark  of  attention.  We 
may  then  define  attention  as  a  complex  of  kinaesthetic  sensa- 
tions which  we  sense  as  effort.  If,  in  turn,  we  emphasized  the 
fact  that  consciousness  follows  the  lead  of  our  feelings,  we 
could  then  define  attention  in  terms  of  the  affections  or  feel- 
ings  which  control  the  direction  of  conscious  activity. 

Bringing  all  these  characteristics  together,  we  have  atten- 
|  tion  defined  variously  as  clear,  active,  selective,  volitional  or 
I  conative,  effortful,  and  affective  consciousness.  But  this  is  a 
I  list  of  the  fundamental  characteristics  of  consciousness  itself. 
What  we  have  been  describing  is  a  whole  state  of  conscious- 
ness. Attention  is  just  consciousness  at  its  best — conscious- 
ness doing  its  work  with  its  greatest  efficiency'  and  despatch. 
Attention  is  not  a  separate  or  independent  function,  but  "the 
mind  at  work  or  beginning  to  work  upon  its  object/'1  It  is  a 
common  and  constant  function  of  all  efficient  consciousness. 
All  processes  and  conditions  of  fully  developed  consciousness 
take  place  in  attention.  Sensation,  perception,  imagination, 
memory,  judgment,  conception,  reason,  emotion,  and  will 
occur  most  completely  at  the  crest  of  the  wave  of  attentive 
consciousness.  Attention,  then,  is  any  state  of  confirimisness 
that  isfully  andjgjapleleJ^consdojisJ_fully  and  effectively 
active. 

~~  Forms  of  Attention. — The  existence  of  many  phases  or 
characteristics  of  attention  makes  possible  a  variety  of  classi- 
fications of  the  kinds  of  attention.  Since  all  of  these  char- 
acteristics are  not  equally  present  in  all  cases  of  attention, 
their  presence  or  absence  forms  a  basis  of  classification. 
Attention — Baldwin's  "Dictionary  of  Philosophy  and  Psychology;' 


ATTENTION 


59 


Attention  is  sometimes  set  up  and  controlled  by  the  inten- 
sity and  character  of  outside  stimuli,  and  sometimes  by  the 
activity  of  consciousness  itself,  i.  e.,  by  conscious  plans  or 
purposes  within  the  mind.  Again  some  cases  of  attentive 
i  consciousness  show  a  marked  degree  of  effort  and  strain, 
while  other  cases  contain  very  little  or  none  at  all.  Some- 
times attention  is  occupied  by  sensory  stimulation  and  ma- 
terial objects,  and  sometimes  it  is  absorbed  in  the  intellectual 
processes  of  memory,  judgment,  and  reason.  The  classifica- 
tion of  the  forms  of  attention  varies  accordingly  as  we  em- 
phasize one  or  the  other  of  these  facts. 

One  of  the  most  popular  classifications  is  that  which  di- 
vides attention  into — 

1.  Non- voluntary  attention. 

2.  Voluntary  attention. 

3.  Involuntary  attention. 

Non^voluntary^  attention  is  the  attentionjgivgn  jto_aiiy 
mental  content  without  being  directed  or_controlled^  by^  con- 
scious  purpose  or  attended  by^  effort  oj^ny_kjricL  In  popular 
'  language  we  say  that  itlsaUelrtionw^owrthe  will.  Non- 
voluntary  attention  may  occur  in  young  children  before 
conscious  purpose  is  developed  when  the  direction  of  their 
thoughts  is  determined  by  influences  outside  of  themselves, 
and  in  adults  when  conscious  purposes  are  in  abeyance.  In 
the  case  of  the  child,  sounds,  colors,  lights,  and  moving  ob- 
jects will  easily  attract  and  hold  his  attention.  As  he  grows 
older,  familiar  and  interesting  topics  of  thought  will  capture 
his  attention  without  effort  or  purpose  on  his  part.  In^thei] 
casej)f  the  adult  ^non-wlu^arv_atterition  is_ found  jn_  flights  i 
of  fancy,  day-dreaming7and~whenweliavebecome  thoroughly  \ 

~"T~* — T"r— s""^^ — " — """? —     —     .—        —    ,i        i  _,  i  _,  .  _,  irq«y» 

absorbejiirispineintoestn^ 

wKerejiffoH^^  '| 

attention.  Non-voluntary  attention  has  sometimesBeen 
cafi&Tspontaneous  attention.  It  is  spontaneous  only  in  the 
sense  that  it  springs  up  without  self-constraint,  and  repre- 
sents the  native  and  acquired  tendencies  that  are  firmly  im- 


6o 


PSYCHOLOGY 


planted  within  us.  First  our  organic  needs — food  and  shelter 
stimuli,  and  situations  which  call  for  actions  of  self-defense 
— attract  and  hold  the  attention.  Later,  the  things  that  are 
in  conformity  with  our  acquired  characteristics  and  touch 
the  chords  of  our  maturer  nature  appeal  successfully  to  the 
attention. 

Voluntary  attentjonvs,  the  jittention_we_give  as^  a  result  of 
someconicious  purpose  or  plan  which  we  wish  to  carry  out, 
Klis  always  attended  ^y^ie^lmgj^gr^rToTFalid  Vtoin  It  is 
f  attention  with  wHT  Plainly,  voluntary  attention  is  possible 
only  where  mental  development  has  reached  a  certain  degree 
of  perfection,  for  it  involves  the  presence  in  the  mind  of  j)ur- 
poses  and  desires  which  are  the  result  of  past  experiences, 
and  which  are  represented  in  consciousness  as  a  future  mode 
of  activity.  Vojuntar^attention  is  evidently  an  outcome,  of 
nnn-Yo.il i n  ta  ry  a  f  f-pn  tipn  Conscious  purpose  and  choice  can 
arise  in  the  mind  only  as  an  outcome  of  a  conflict  in  non- 
voluntary  attention.  \Vhen  tjyo^p^m^re^jy^l^tmmji  Jjjci 
foj^J.he_ceirtraJ_^ 
attention^rjecomesDOSsible  as  self -initiated  and  self-directed 


consciousness.  What  enters  the  mind  then  is  determined  by 
premeSita-teoT'  choice.  Voluntary  attention  may  be  trans- 
formed into  non-voluntary  or  spontaneous  attention.  Where 
at  first  we  attend  with  conscious  effort  and  with  difficulty, 
we  in  tune  come  to  attend  spontaneously,  and  therefore  with- 
out effort.  Voluntary  attention,  then,  has  both  its  beginning 
and  its  end  in  spontaneous  attention. 

In-voluntary  ^/g^Q^s^thg^^ttejitig^ 
ect  ortopic  of    hought  in^jyaijj^  of  J_oj^njdi^ 


our  desire  to  attend  to  something  else.  It  is  attention  against 
th^\^flir~TTie~tlmig  we  atfencTecTEo  forces  itself  upon  us  even 
though  we  strive  to  keep  it  out  of  our  consciousness.  In- 
tense stimulation  of  any  kind,  loud  or  sudden  sounds,  bright 
lights,  abrupt  changes,  moving  objects,  bodily  pain,  insistent 
or  fixed  ideas,  consuming  sorrows  and  alluring  pleasures,  all 
force  themselves  into  the  centre  of  our  consciousness,  in  spite 


ATTENTION  6 1 

of  our  effort  to  keep  them  from  entering.  This  form  of  atten- 
tion should  not  be  confused  with  non- voluntary  attention, 
for  while  rnvoluntary^ajioriiiolf^  aji£'e 

in^  the  fact  that  it  is_jthe  jorce_of^the  stimulus  itself  rather 
than  any  purpose  in  the  mind  that  starts  the  attention  proc- 

— — — •* 'li    •         '  — -•          >    - ^  _»— ^— ___ .>__  .        —  ^       — *          •*  -  *^V~l» 

ess,_involuntaryj attejitioji_jsjilwj^^  ^y 

against,  or  away  from-the  incoming  stimulus  or  topic  of6"***^ 

-^^— —    ,jf       - J I  |       _, ,  _   *^ — „       _       _^ -C^—^       _          | yj    >JL 

jthe  attention.     However,  it  is  evi- 


dent that  the  things  that  do  succeed  in  taking  the  citadel  of 
our  consciousness  by  storm  are  the  things  that  awaken  our 
spontaneous  or  non- voluntary  attention.  From  this  point  of 
view  involuntary  attention  is  the  old  non-voluntary  atten- 
tion come  back  to  us. 

Another  classification  of  the  forms  of  attention  which  has 
been  even  more  popular  than  the  preceding  one  is  that  which 
/jdivides  attention  into — 
i.  Passive  attention. 
Active  attention. 

Passive  attention  corresponds  very  closely  to  non-volun- 
,ry  or  spontaneous  attention.     When  an  intense  or  sudden 
/  ft/stimulation  forcibly  breaks  into  our  consciousness,  or  when 
f-fl  f   some  insistent  idea  takes  possession  of  us,  we  are,  in  respect 
l£  \     to  the  initiation  of  the  attention  process,  passive.     We  do 
not  start  the  process;  something  outside  the  self  commands 
it.     The  term  passive,  however,  is  a  misnomer  if  it  is  used  to 
describe  the  attention  process  itself,  for  all  attention  is  active 
once  it  is  set  up.     "Passive"  refers  only  to  the  fact  that 
attention  may  be  determined  by  something  which  is  out- 
side of  the  self,  not  that  the  attention  process  itself  is  pas- 
sive. 

Active  attention,  on  the  other  hand,  is  self-determined. 
i.  e.,  we  take;  thfi  jnitiative  in  starting  and  maintaining  the 
process.  It  is  really  voluntary  attention.  When  we  attend 
because  of  some  conscious  purpose  or  plan  in  our  mind  we 
are  active  in  initiating  the  attention  process.  Active  atten- 
tion is  always  the  result  of  effort  and  is  attended  by  strain- 


62  PSYCHOLOGY 

sensations,  while  passive  attention  requires  no  effort  on  our 
part  and  is_free  fromstrain-sensat4pns.  at  ^east  in  its  initial 
stag?. 

Passive  attention  may  easily  pass  into  active  attention; 
e.  g.,  the  forcible  presentation  of  some  object  may  start  a 
voluntary  train  of  thought  or  an  active  examination  of  the 
object  in  conformity  to  some  plan  which  we  wish  to  carry 
out. 
i  Still  another  classification  divides  attention  into — 

1.  Sensory  attention. 

2.  Intellectual  or  ideational  attention. 

This  classification  does  not  consider  the  attention  process 
itself  so  much  as  the  kind  of  material  upon  which  the  atten- 
tion works. 

Sensory  attention  is  the  attention  we  give  to  the  object 
which  stimulates  the  sense-organs.  Its  direction  is  therefore 
determined  by  our  environment.  Sensory  attention  is  also 
in  many  cases  non- voluntary  and  passive  attention,  but  it  is 
not  coextensive  with  these  forms.  For  it  is  evident  that  in  a 
given  environment  we,  ourselves,  may  be  active  in  determin- 
ing the  objects  to  which  we  give  our  attention,  i.  e.,  the  sen- 
sations to  which  we  attend.  In  this  case  sensory  attention 
is  coexistent  with  voluntary  and  active  attention.  Those 
cases  of  passive  attention  where  memories  or  ideas  force  the 
attention  lie,  of  course,  outside  of  sensory  attention. 

Intellectual  or  ideational  attention  is  the  attention  we  give 
in  memory,  imagination,  judgment,  reason;  in  short,  in  all  the 
mental  processes  other  than  sensation  and  perception.  Most 
of  the  cases  of  intellectual  attention  fall  also  under  voluntary 
and  active  attention,  although  not  all  of  them.  For  instance, 
in  cases  of  attention  set  up  by  insistent  or  fixed  ideas,  atten- 
tion is  both  intellectual  and  non-voluntary,  or  passive. 

In  much  of  our  conscious  life  these  distinctions  between 
the  forms  of  the  attention  are  not  present  as  absolute  lines  of 
demarcation.  The  Joans  of  attention  ™^g**  "^p  each  qther 
or  are  present  in  ^n^st^ff  nf  ronnr '""sr^s  injyarying  degrees. 


I 


ATTENTION  63 

Oftentimes  it  is  impossible  to  determine  whether  we  are 
attending  because  of  some  purpose  in  our  minds,  or  because 
of  the  intensity  of  the  outer  stimulus.  Both  influences  may 
be  at,  work.  Again,  a  state  of  consciousness  is  rarely,  if  ever, 
purely  sensory,  for  every  stimulus  awakens  intellectual  proc- 
esses as  well  as  sensory  processes.  What  we  are  conscious  of 
at  liiiy  moment  depends  irTvarying  degrees  upon  both  our 
surroundings  and  upon  the  nature  of  our  present  and  past 
experience.  Sometimes  the  force  of  the  environment  pre- 
dominates, and  sometimes  the  purposes  and  plans  within  us 
are  uppermost  in  consciousness. 

From  the  genetic  point  of  view  these  forms  of  attention 
represent  stages  in  the  growth  and  development  of  conscious- 
ness. Non-voluntary  attention,  passive  attention,  and  sen- 
sory attention  are,  in  large  part,  the  first  kind  of  attention  to 
appear.  How  consciousness  becomes  clear  and  vivid  in  the 
beginning  involves  the  problem  of  how  we  can  be  conscious 
of  an  outside  world  at  all.  At  any  rate,  the  fact  remains  I  j 
tl^at  sense  -stimuli  acting_jipjn^i~ne5^)irs  organism  fnrcpj  I 
their  way  to  consciousness,  and_this_consciousness  is  the!  I 
germ  of  attention.  Whether  ^r  not  they  arouse  clear  and 
definite  awareness  at  first,  they  certainly  occu'py  the  centre 
of  what  consciousness  there  is,  and  call  out  the  native  reac- 
tions of  the  organism.  Bodily  adjustments  and  sense-ac- 
commodations take  place.  Sensations  of  movement  and 
simple  feeling  are  awakened.  The  whole  organism,  mental 
and  physical,  is  centred  upon  the  stimulus.  All  the  essential 
characteristics  of  attention  are  present.  But  jt^is  a  ngtive_ 
or  refiex  ^attention,  the  attention  whicli^he^jorganjsiTL^gi 
because  bv  virtue  of  its  inherent  nature  jt  cannotjioj)ther- 


wise^.  The  organism  is  so  constitu  tethatceirtain  stimuli 
attract  it  spontaneously,  i.  e.,  without  effort  or  constraint  on 
its  part.  In  this  stage  of  development  it  is  the  character  of 
the  stimuli  which  determines  the  selection  of  attention,  i.  e., 
to  what  stimulus  among  the  many  which  present  themselves 
the  organism  will  react.  Stimuli  of  high  intensities  or  of 


//vyv^v*1"™";?  ^^^Mr^^v 
i/l 


PSYCHOLOGY 


certain  qualities,  often-repeated  stimuli,  sudden  changes, 
movement,  the  strange  or  novel,  food  and  shelter  stimuli,  all 
these  possess  a  native  attraction  and  are,  therefore,  attended 
to.  They  have  been  significant  signs  in  racial  development 
and  evolution,  marking  out  the  pathway  of  self-preservation 
for  the  individual  organism.  They  were  signs  of  dangers  to 
be  avoided  or  of  advantages  to  be  gained;  so  the  tendency  to 
react  to  them  has  become  native  and  hereditary. 

A  higher  stage  of  development  shows  the  organism  able 
to  retain  and  reproduce  past  experience.     The  organization. 
of  this  experience  into  a  system  of  self-experience,  any_pa,rt 
oiwhich  can  be  recalled,  forms  a  new  basis  of  control.     As  it 
acquires  experience  Llle  urganTsmn6ecomes  less  and  less  sub- 
ject to  the  domination  of  outside  stimuli.     It  is  able  to  take 
matters  into  its  own  hands,  or,  we  might  say  less  figuratively, 
the^  acquisition  of  new  exnerience_Js  ^determined,  by  the  ng.- 
ture__of  the  old  experience  explicitly  rpp*odiirP,d  aTTl  fr*"™^ 
lated^  into  purpose,  plan,  or  desire^.   Or,  to.  put  the  same 
matter  in  another  way,  the  old  experience  a^sjmilatea_rJie, 
.  new.__What  we  attend  to  in  this  stage  of  development  is 
'determined  by  the  experience  we  can  reproduce  from  past 
states  of  attention.     Effort  and  strain-sensations  appear  as  a 
result   of   sensory   and   bodily   adjustments   we   consciously 
make.     Moreover,  the  effort  appears  as  self-effort,  because 
A  it  follows   or   accompanies   the   conscious  plan   or  purpose 
U  within  the  mind.     We  now  attend  because  we  will  to  attend. 
'This  is  voluntary  attention,  active  attention,  or  intellectual 
attention.     It  has  grown  directly  out  of  the  preceding  stage 
of  non-voluntary,  passive,  or  sensory  attention1  in  so  far  as 

1  It  has  already  been  noted  that  sensory  and  intellectual  attention  are  not 
coextensive  with  non-voluntary  and  voluntary  attention.  Part  of  sensory 
attention  may  come  under  voluntary  attention;  e.  g.,  one  may  voluntarily 
attend  to  some  sense-stimulus.  Or  intellectual  attention  may  be  non-volun- 
tary after  voluntary  attention  has  been  transformed  into  acquired  non-volun- 
tary attention;  e.  g.,  the  student  may  attend  without  effort  to  his  exercises  in 
logic  after  he  has  thoroughly  mastered  them.  However,  in  the  beginning  non- 
voluntary  attention  is  largely  sensory  attention. 


ATTENTION  65 

these  last  forms  of  attention  are  evoked  by  the  character  and 
force  of  external  stimuli. 

A  still  higher  degree  of  development  appears  when  vol- 
untaryattentionin  any  particular  field  loses  its  effort  and 
self-constraint  and  becomes  spontaneous.  This  represents 
trie  highest  stage  ot  mental  development  and  efficiency. 
With  respect  to  the  attention  it  may  be  designated  as  a<> 
quired  spontaneous^^  In  time  we  come  to  attend  spontane- 
ously, and  in~quite  as  free  and  unconstrained  a  manner  as 
in  native  spontaneous  attention,  to  our  studies  and  our  work. 
Art,  literature,  and  science  may  become  second  nature. 
They  may  appeal  to  us  and  challenge  our  attention  unaided 
by  any  effort  on  our  part. 

In  the  order  of  development,  then,  consciousness  first  »A 
shows  itself  as  native  or  reflex  attention.  Out  of  this  develops 
effortful  OT^voluntary  attention,  representing  the  stage  of  self- 
growth  and  self-development.  Then  comes  acquired  spon- 
taneous attention,  representing  the  stage  of  self-mastery  and 
achievement:  " 

If  now  we  review  all  the  forms  of  the  attention  we  shall 
ind  that  there  is  one  characteristic  that  is  universally  pres- 
ent. We^  refer,  of  course,  to  the  characteristic  of  clearness 


However  attention  may  be  determined — by  the  externa 
stimulus,  by  conscious  purpose,  or  by  sensory  or  intellectua 
activities — the  attention  itself  is  clear  consciousness,  i.  e.,  ir 
attention  we  are  more  keenly  conscious  of  some  objects  thar 
of  others,  of  some  topics  of  thought  than  of  others. 

Clearness  must  not  be  confused  with  high  intensity  or 
opposed  to  low  intensity  of  stimulation.  A  low  degree  of  a 
sensation  may  be  perfectly  clear  in  consciousness,  or  a  high  de- 
gree may  not  be  attended  to  at  all,  i.  e.,  it  may  not  be  clear. 

For  instance:  the  pop  of  a  tiny  firecracker  may  be  per- 
fectly clear  in  consciousness,  while  the  boom  of  the  cannon, 
although  present  in  consciousness,  may  not  be  attended  to 
and  therefore  may  not  be  clear.  The  sound  may  have  a  high 
degree  of  intensity  but  a  low  degree  of  clearness.  It  is  true 


PSYCHOLOGY 

that  high  intensity  usually  attracts  attention  and  becomes 
clear,  and  that  low  degrees  of  intensity  escape  attention,  but 
clearness  and  intensity  are  different  attributes  of  conscious- 
ness. Whether  attention  increases  the  intensity  of  a  sensa,- 
tion  or  not,  g/ff.,  whetheracontimipjis__souncL  of  constant 
objective  intensityj:hanges  its  intensity  when  we  attend  ^p 
it,is  aZfluegtion  "atTpresent  irTdispute.1  it  is  evident,  how- 
ever,  that  if  there  is  any  change  in  the  intensity  of-  presenta- 
tion when  it  reaches  the  focus  of  attention,  the  change  is  so 
slight  that  it  escapes  ordinary  observation. 

It  is  a  common  belief  in  popular  thought  that  the  degree 
•\$)f  attention  is  proportionate  to  the  amount  of  effort  expended 
'   *^n  attending.     The  more  effort  we  put  forth  the  higher  the 
r      (/*>  degree  of  attention.     This  is  true  only  within  very  narrow 
'limits.     In  voluntary  attention  it  requires  effort  to  direct 
and  hold  the  attention,  and  for  a  short  time  the  degree  of 
attention  increases  with  the  amount  of  effort.     But  in  the 
higher  degrees  of  attention,  absorbed  or  rapt  attention,  there 
is  no  observable  effort  at  all.     If  one  becomes  deeply  atten- 
tive all  effort  to  attend  disappears.     This  is  true  in  all  cases 
of  acquired  spontaneous  attention.     A  better  measure  of  the    . 
degree  of  attention  is  the  despjUxjjjmdj^fi.dejK^^^  r* 

certain  ^n^miljarTa^s^r£pei£o^m£ciijg.  g.,  thejtim^recjuirecl, 
to  learn  a  certain  numberof  nonsense-syllables  or  the  accu- 
racy^andThe  time  requirecTto  cross  out  the  "a's"  on  a  page 
^printed  matter.     Another  measure  is  to~~~note  tne  strength 

a  distracting  stimulus  necessary  to  produce  a  decrease  in 
efficiency  with  which  one  performs  a  task  requiring  close 
attention,  and  use  that  as  a  measure  of  the  degree  of  attention. 

Still  another  method  is  to  take,  as  a  measure  of  attention,2 

1  A  minimal  degree  of  intensity  which  lies  just  below  the  threshold  of  non- 
attentive  consciousness  may  be  raised  above  the  threshold  when  the  attention 
is  turned  upon  it,  i.  e.,  one  can  hear  the  ticking  of  a  clock  when  attention  is 
given  to  it,  while  without  attention  it  is  inaudible.  This  may  not  be  due  to  an 
increase  in  intensity,  however. 

2Oehrn:  "  Experimentelle  Studien  zur  Individualpsychologie,"  Psych.  Ar~ 
beilen,  I. 


ATTENTION  67 

the  variations  which  we  make  in  a  series  of  accurate  rnpasnre- 
ments  under  the  same  conditions.     Say,  for  instance,  one  is 
measuring  the  length  of  a  screw  to  thousandths  of  an  inch, 
and  several  series  of  ten  measurements  each  are  made.     It  is 
evident  that  the  higher  the  degree  of  attention  given  to  any 
series  of  measurements  the  less  the  variation  in  the  individ- 
ual measurements  will  bel    The  mean  variation,  or  the  aver-l\ 
age  departure  from  the  average  measurement  in  any  series  ]\ 
would  be  an  indication  of  the  degree  of  attention  given  injj 
the  series.     In  some  series  the  variation  would  be  small,  in 
others  large,  and  since  the  variations  must  be  in  the  mental 
factors,  we  can  reasonably  suppose  that  the  most  important 
factor — ajlejition— is  the  variable  element.     Obviously  none 
of  these  methods  measures  attention  itself. 

What  is  commonly  spoken  of  as  inattention  is  not  a  state 
of  attention  at  all,  but  absolute  non-attention.  When  we 
say  mat  a  schoolboy  is  inattentive  to  his  lessons  it  is  often- 
times true  that  he  is  deeply  attentive  to  something  else — the 
drawing  of  the  teacher  he  is  making  or  the  bent  pin  that  he 
intends  placing  on  the  seat  of  his  enemy  across  the  aisle. 
The  enterprise  in  which  he  is  engaged  has  completely  dis-, 
placed  the  lesson.  There  is,  however,  a  positive  state  of 
attention  which  has  inappropriately  been  called  inattention. 
It  is  attention  of  a  low  order  and  exists  in  the  general  forms 
of  wandering  attention  and  _di$p£Ksed  attention.  In  wandering! 
attention  consciousness  is  abnormally  unstable,  flitting  from  I 
one  thing  to  another  so  rapidly  that  it  is  inefficient.  In  dis-  * 
persed  attention  objects  and  ideas  do  not  stand  out  clearly 
and  distinctly.  Mental  states  are  not  focalized  sharply,  and 
so  cojnsjdojisjie^JsJihirxed-_and  hazy.  These  forms  of  atten- 
tion are  frequently  the  signs  of  inanition,  anaeinja,  a  general  P 
lowered  bnHily  condition,  fatigue,  orjrven  of  mental  dise^ 

Neural  Basis  of  Attention. — If  now  we  ask  what  the  brain 
conditions  are  that  are  concomitant  with  clear  and  vivid 
states  of  consciousness,  we  are  forced  to  theorize,  for  the 
physiological  facts  concerning  the  neural  activities  in  the 


68  PSYCHOLOGY 

brain  areas  during  consciousness  have  not  yet  been  made 
out.  We_jnj,y  fairly  a^mie^Jiavvever^  that  definite  states 
of  consciousness  nlvdejntectitiertain  brain 


^  _ 

centres;  that  .the  neural  excitement  Jnjjiese  Centres  is  for  the 
moment  rais^cTabpve  that  jn^  othe£centres;that  changes  in 
attention  correspond  to  changing  areas  of  excitement  or  ten- 
Now,  we  have  seen  that  there  are  in  gen- 


eral  two  factors  which  determine  the  direction  of  attention: 
(i)  the  nature  of  the  external  stimulus  (bright  lights,  loud 
and  sudden  sounds7etc.j,  and  ^2)  thejiature  of  consciousness 
itself  (effect  of  past  experience,  conscious  plans  and  purposes, 
and  ideas  present  in  the  mind).     If  some  external  stimulus, 
\\  by  virtue  of  its  character,  forces  the  attention,  we  can  con- 
U  ceive  the  neural  activity  as  working  upward  from  a  lower 
i  level  or  lower  unit  to  a  higher  level  or  higher  unit  of  nervous 
|  activity;  i.  e.,  the  stimulus  first  raises  the  activity  in  a  par- 
ticular sense  centre  above  that  in  the  other  parts  of  the  brain, 
and  then  drains  off  into,  or  involves  the  activity  of,  a  higher 
neural  unit  or  level  which  has  previously  been  associated 
with  the  activity  of  the  sense  centre.     The  particular  way 
.we  may  attenclto  the^given^stimulus^Jhe  way  we  perceive,  it. 
Js    risdetgrinineJ^Ev^  in  th&  past. 

Air  .  Vl^  b3M;Ee~l:m^^  e.  'g.,  the 

y  way  in  which  I  attend  to  the  ringing  of  a  bell  outside  — 
/  .A  J  whether  I  perceive  it  as  a  street-car  bell  or  as  that  of  a  baker's 
\j  iy  "/  wagon  depends  upon  my  past  experiences  and  my  present 
v'  A/  surroundings. 

'/  •      This  means  that  at  any  moment  certain  brain  centres  are 
more  susceptible  than  others.     Some  authorities  hold  that 
^  y^J'A  this  greater  susceptibility  of  some  centres  over  others  is  due 
jy  vjfn  to  facilitation,  others  think  that  it  is  due  to  i^hibitioji  of 
\  JA/V   \rival  centres,  and  still  others  are  of  the  opinion  that  both 
processes  are  at  work.  *  Facilitation  means  that  theactiorjjn 
nnej^nun  rejitr^  (^  Iher^isprTTT^^ 

in£nja5es_4he->^(cj;ion^^  Inhibition  means 

that  the  action  in  the  centres  not  involved  in  the  attention- 


ATTENTION 


consciousness  is  lessened  or  blocked  by  the  action  of  a  higher 
centre.  Thus  if  I  attend  to  the  bell  as  that  of  a  street-car, 
the  centre  involved  in  "street-car  perception"  is  facilitated, 
and  the  centre  corresponding  to  " baker's  wagon"  is  inhib- 
ited. 

In  the  case  where  attention  is  determined  by  conscious 
purpose  or  plan,  where  we  select  one  from  several  presented 
stimuli,  we  may  conceive  of  the  neural  activity  as  working 
downward  from  higher  units,  and  facilitating  the  action  in 
the  centres  involved  in  the  particular  attention-conscious- 
ness, or  as  inhibiting  the  action  of  all  other  centres.  Thus  if 
I  determine  to  listen  to  the  faint  strains  of  a  distant  street- 
organ  rather  than  the  nearer  and  louder  noises  of  the  street, 
certain  centres  are  facilitated  and  all  others  are  inhibited  or 
blocked  for  the  moment. 

Whether  there  are  definite  brain  centres  whose  function 
it  is  to  control  these  processes  of  facilitation  and  inhibition 
in  attention,  or  whether  any  part  of  the  higher  brain  may  so 
act,  is  not  known.  It  has  been  suggested  that  the  so-called 
associational  areas jn^tEeJrontanobes  oTtKe]gor1^x]are^on£ 
responsible  for  the  fa^mrtalio^s~andTnhibitions  in  the  play  of 

-M.-1--*-  .     ,     __  -  _ - «"— — - ^-  -— — -—^— LJT— -*— ^_  ^***~~**±^~^**+  t*» 

attention-consciousness..     Pathology  has  determined  the  fact 


that  lesions  in  this  part  of  the  brain  involve  impairment  of 
the  attention  especially.  Comparative  neurology  shows  that 
the  size  of  these  frontal  areas  goes  hand  in  hand  with  the 
development  of  attention.  We  also  know  that  in  very  young 
children,  before  sustained  attention  is  possible,  the  frontal 
areas  are  not  yet  matured — that  the  nerve-fibres  in  this  area 
have  not  acquired  their  myelin  sjieath,  and  are  not,  therefore, 
ready  to  function. 

However,  in  view  of  the  paucity  of  detailed  facts  in  the 
anatomy  and  physiology  of  the  nervous  system,  we  must 
suspend  judgment  concerning  the  neural  basis  of  attention. 
It  is  all  very  vague  and  indefinite  as  yet.  We  can  only  hope 
that  the  rapid  development  in  these  sciences  will  throw  more 
light  upon  the  question. 


1 


PSYCHOLOGY 


FIG.  32. 


Shifting  of  Attention. — -We  have  already  noted  the  chang- 
ing aspect  of  consciousness  in  attention.  No  mental  content 
remains  clear  long — it  rises  and  falls  intermittently.  This 

changing  of  attention  is  observ- 
able in  topics  of  thought  in- 
volving the  higher  mental  proc- 
esses, memory,  imagination, 
judgment,  et  cetera;  in  the  per- 
ception of  objects,  and  in  mini- 
mal sensations  coming  from  stim- 
uli of  very  low  degree  of  intensity, 
i.  e.,  sensations  which  lie  just  on 
the  lower  threshold  of  conscious- 
ness. If  we  try  to  fix  some  one 
topic  of  thought,  we  find  it  im- 
possible to  hold  any  one  aspect 
of  it  clearly  in  consciousness  for 
any  length  of  time.  Thinking  of 

one  thing  means  that  one  after  another  of  its  aspects  be- 
comes clear  in  rapid  succession.  The  content  of  focal  con- 
sciousness is  always  changing.  The  same  fluctuations  occur 

when  we  attend  to  objects.     This 

• 
is  illustrated  in  the  perception  of 

ambiguous  figures.  If  we  look  at 
Figure  32,  we  perceive  it  as  a  card- 
board  bent  toward  us,  changing 
the  next  instant  into  a  cardboard 
bent  away  from  us.  These  two 
aspects  of  the  figure  alternate  in 
consciousness. 

Observe  the  changing  percep- 
tions  of  Figure  33 :  It  may  appear 
as  four  lines  of  horizontal  dots ;  or 

four  lines  of  perpendicular  dots;  or  as  diagonal  lines  of  dots; 
or  as  four  squares;  or  as  two  squares,  a  smaller  one  included 
in  a  larger  one;  or  in  various  other  arrangements. 


FIG.  33. 


ATTENTION 


A  special  case  of  the  fluctuation  of  perceptions  is  seen  in 
binocular  rivalry.     Hold  the  open  hand  up  before  the  right 
eye,  select  some  object  in  the  room  that  is  screened  entirely 
from  the  right  eye  but  is  in  plain  view  of  the  left  eye.     Fix  ^    .*< 
the  attention  on  the  object  and  it  will  apparently  be  seen  » ^ 
through  the  hand.     Part  of  the  time  it  will  stand  out  clear 
and  distinct,  part  of  the  time  it  will  be  indistinct  or  even 
disappear   completely,   displaced   by   the  perception   of   the 


FIG.  34. 

hand  that  lies  between  you  and  the  object.     The^xpjanation 
is  in  the  fact  that  part  of  the  time  you  see  more  clearly  with 
one  eye  and  part  of  the  time  with  the  other.     If  a  stereoscopic  ( 
card  is  prepared  with  one-half-inch  colored  squares,  red  for  \ 
the  right  eye  and  green  for  the  left  eye,  and  is  then  placed  , 
in  the  stereoscope,  the  red  square  is  exposed  only  to  the  right, 
eye  and  the  green  square  only  to  the  left  eye.     Under  these | 
conditions  both  squares  seem  to  occupy  the  same  position  in 
the  visual  field,  but  only  one  of  them  is  present  in  conscious- 
ness at  a  time.     They  alternate  in  a  continuous  rivalry,  first 
one  and  then  the  other  taking  possession  of  consciousness. 
The  periods  of  fluctuation  vary  slightly  in  duration  with  dif- 
ferent subjects,  but  they  average  about  two  seconds  in  length. 
Now  we  find  that  the  length  of  time  that  one  of  these  colored 
fields  remains  clearly  in  consciousness  is  influenced  by  the 
same  factors  that  accompany  attention.     If  one  field  is  more 
intense  than  the  other  it  remains  in  consciousness  longer. 


72  PSYCHOLOGY 

Likewise,  if  one  field  has  more  complexity  (lines  and  figures 
drawn  upon  it),  or  if  eye  movements  or  adjustments  are 
made  in  conformity  to  the  lines,  or  if  one  field  is  more  strik- 
ylng  in  novelty,  or  is  more  pleasing,  it  remains  in  conscious- 
ness longer  than  the  other.1 

Hold  an  ordinary  envelope  between  the  eyes  close  to  the 
face  so  that  the  circle  (Figure  34)  is  cut  off  from  the  right  eye. 
Fixate  the  square  and  the  circle  will  disappear  and  reappear. 

The  same  phenomenon  can  be  observed  where  one  object 
is  in  the  margin  of  the  visual  field,  and  another  in  the  central 
portion. 


FIG.  35. 

Fixate  the  right  dot,  which  should  be  placed  directly  in 
front  of  the  right  eye  and  about  four  inches  away;  look  at  it 
steadily  for  some  time.  The  left  dot  will  disappear  and  re- 
appear. 

When  the  attention  is  turned  to  continuous  minimal 
stimuli  the  sensations  resulting  from  them  appear  inter- 
mittently in  consciousness.  Periods  of  clearness  and  periods 
of  obscureness  or  total  disappearance  can  be  observed.  If, 
for  example,  the  attention  is  fixed  upon  a  very  faint  gray  line 
just  discernible  upon  a  white  background,  it  will  remain  in 
clear  consciousness  only  a  short  time,  disappearing  and  reap- 
pearing. Masson's^disc  is  a  simple  illustration  of  this. 

A  still  simpler  way  to  get  the  fluctuation  is  to  fixate  some 
spot  on  the  wall  that  is  barely  visible.  Faint  auditory  stim- 
uli (the  faint  ticking  of  a  watch  or  the  sound  of  a  stream  of 
fine  sand  falling  on  a  blotting-pad)  are  also  intermittently 
clear  and  unclear.  Tn  the  case  of  faint  pressures-gustatory, 
o  £ and  olfactory  sensations,  fluctuation  is  510.  t  **  pviHpnt,  Taste 
•  and  smell  sensations  do  "change  in  clearness,  but  since  it  is 
impossible  to  get  a  constant  stimulus  in  these  cases  the 

1  Breese:  "On  Inhibition,"  in  Psych.  Rev.,  Mon.  Sup.  III. 


ATTENTION 


73 


changes  might  be  due  to  changes  in  the  stimulus.  Inhala«- 
tion  and  exhalation  are  constantly  changing  the  intensity  of 
the  stimulus  in  the  one,  and  the  varying  chemical  changes  of 
food  in  the  other.  Pressure-sensations  sometimes  show  a 
less  observable  fluctuation ,  aqd 
here  the  varying  blood-pressure 
may  change  the  effect  of  the  stim- 
ulus, too.  In  fact,  it  has  been 
claimed  by  some  that  all  these 
fluctuations  in  perceptions  and 
minimal  sensations  are  not  due  to 
the  attention  at  all,  hut  to  the 
accommodation  of  the  sense- 

and   no    doubt    this"  has. 

FIG.  36. — Masson's  disc. 
When  a  disc  of  this  kind  is 
rotated,  the  short  black 
lines  give  a  series  of  faint, 
gray  rings  which  grow  fainter 
toward  th»  circumference. 
The  outer  rings  are  barely 
visible.  Fixate  one  of  the 


organs^ 

mudl^tp  do  witlj.  it.  'rne  lens  of 
the  eye  changes  its  curvature  pe- 
riodically, thereby  changing  the 


faintest  rings  and  it  will 
disappear  and  reappear  peri- 
odically. 


sharpness    of    the    retinal  image. 
The  muscles  of  the  ear  contract 
and    relax,    varying    the    tension 
of  the  drum.     Moreover,  the  pe- 
riods of  oscillation    in   conscious- 
[  ness  have  been  observed  to  corre- 
™  spond  to  these  changes  in  accommodation  in  the  sense-organs. 
So  the  question  whether  the  shifts  in  consciousness  are* 
due  to  changes  ^  ot^a^amniod^o^ 

organs  or  to  "fluctuation  of  the  attention"  is  pertinent.  I 
Against  Tn^^elipTiery^trieory^  has  been  offered  the  fact  that 
fluctuations  in  visual  sensations  have  been  observed  in  cases 
where  the  muscles  of  the  lens  and  pupil  have  been  tempo- 
rarily paralyzed  by  atropin;  also  where  the  lens  has  been 
removed  by  operation.  In  cases  where  the  drum  of  the  ear 
has  been  destroyed,  fluctuation  occurs  in  auditory  sensations. 
But  this  is  not  conclusive.  The  absence  of  the  lens  of  the 
eye  does  not  preclude  the  possibility  of  fluctuation  of  sensi- 
tiveness to  light-stimuli  in  the  retina,  the  real  sense-organ  of 


-2 

" 


74  PSYCHOLOGY 

vision.  There  is  reason  to  believe  that  the  delicate  nerve- 
endings  in  the  retina  undergo  rapid  chemical  changes,  and 
that  these  changes  affect  their  sensitiveness.  This  might 
well  account  for  the  fluctuation  of  minimal  light-sensations. 
Likewise,  there  may  be  other  sense-organ  adjustments  in  the 
ear  than  those  of  the  drum,  and  they  may  account  for  the 
fluctuations  of  minimal  auditory  sensation.  It  is  therefore 
doubtful  whether  these  fluctuations  are  due  to  changes  in 
attention  or  to  end-organ  adjustments.  In  some  cases  we 
are  reasonably  sure  that  they  are  due  to  the  latter. 

For  instance,  in  the  case  of  the  alternating  red  and  green 
squares  in  the  stereoscope,  if,  when  I  give  my  attention  to  the 
red  square,  the  green  square  displaces  it  in  sensory  conscious- 
ness, I  may  still  be  thinking  about  the  red  square,  attending 
to  its  quality,  size,  et  cetera,  so  that  the  change  in  conscious- 
ness is  not  a  change  of  attention.  What  really  happens  in 
this  case  is  that  part  of  the  time  I  am  attending  to  the  sen- 
sory perception  of  the  red  square,  and  part  of  the  time  to  its 
memory  image.  On  the  other  hand,  the  green  square  may 
not  occupy  clear  or  attention-consciousness  at  all.  When  the 
green  square  is  in  consciousness  the  mental  image  of  the  red 
square  is  still  clear,  while  the  sensory  experience  of  the  green 
square  is  marginal.  In  the  case  of  the  disappearing  faint 
gray  ring  of  Masson's  disc,  I  may  still  continue  to  attend  to 
it  after  the  gray  ring  itself  has  disappeared,  by  holding  it  in 
mind  as  a  mental  image.  In  other  cases  of  minimal  sensa- 
ftions  where  the  sense-organ  is  not  supplied  with  delicate 
movements  of  accommodation,  as,  for  instance,  in  very  light 
Ipressure-sensations,  attention  is  able  to  maintain  itself  with- 
,out  change  for  very  much  longer  periods. 

Physiologically  there  are  two  factors  to  consider  in  these 
changes  of  consciousness:  (i)  the  sense-organ  activity  and 
movements  of  accommodation^  and  (2)  the  central  or  cortical 
activity  in  trie  Dram!  Changes  in  attention  are  due  to 
changes  in  the  central  brain  activity — fatigue  in  the  cortical 
cells,  changes  in  blood-supply,  anabolic  and  catabplic  proc- 


ATTENTION  75 


esses,  et  cetera.  NowL  wfrjlf  -the  renf.ra.1  activities  in  the 
brain  are  sometimes  the  result  of  the  nervous  impulses 
from  sense-organs  T  the 

central  neural  activities  corresponding  to 
attention  must  be  conceived  as  including  larger  brain  areas 
than  the  areas  involved  only  in  the  reception  of  sense-stimu- 
lation and,  when  once  set  into  action,  as  continuing,  even 
though  the  sense-organs  are  inactive.  For  instance,  if  I 
attend  to  a  certain  book  on  my  desk,  my  attention  may 
involve  more  than  the  brain  activity  in  the  visual  centres. 
Past  associations  and  consciousness  of  the  relationship  to 
other  objects  may  be  present.  If  the  book  is  removed  from 
my  sight  I  may  go  on  attending  to  it.  Or  if  an  inkstand  is 
put  in  its  place  I  may  still  attend  to  the  book  and  at  the 
same  time  be  conscious  of  the  inkstand.  But  in  this  case  the 


inkstand  is  not  in  the  focus  of  attention.     So  we  infer 
the  brain  activities  corresponding  to  attention-consciousness  J 
involve  larger  areas  than  those  corresponding  to  mere  sensa- 
tion or  perceptioji..    We  conciude7  therefore,  that  attention 

may   rVmr^   witVi    fViA    ^V.Qr.nr^c   r>f  g^r.gg-ctirniiH   nr  ma.v   art 
independently  of  them  ___  Shifting  of  the  attention  involves 
more  factors  than  those  involved  in  the  fluctuation  of  mini- 
mal sensations  or  in  the  rivalry  of  objects  presented  to  the 
sense-organs.     While  attention  cannot  hold  itself  indefinitely  j 
to  one  thing,  it  is  not  limited  so  far  as  its  maximum  duration  I 
is  concerned  to  the  very  short  periods  which  characterize  the!  z 
fluctuation  of  minimal  sensations,  i.  e.,  four  to  eight  seconds.*   ' 

If  we  keep  in  mind  the  fact  that  the  real  function  of 
consciousness,  in  all  stages  of  development,  has  been  to  aid 
the  organism  in  its  adaptive  adjustments  to  its  environment,  / 
we  can  see  why  it  is  the  nature  of  attention  to  shift.     InA. 
order  to  survive,  the  organism  has  been  forced  to  react  quickly   * 
to  a  rapidly  changing  environment.     One  object  after  an- 
other has  presented  itself,  and  to  each  one  in  turn  bodily 
adjustments  had  to  be  made.     Presentation  of  an  object, 
recognition  of  it,  adaptive  reaction,  presentation  of  another 


PSYCHOLOGY 

bject,  recognition  of  it,  another  reaction,  and  so  on  in  an 
ver-changing  series  of  presentations  and  reactions,  with  con- 
fciousness  mediating  between  them — such  has  been  the  his- 
ory  of  development.  Now,  each  recognition  and  adaptive 
action  has  required  only  a  short  space  of  time.  Conscious 
fe  has  developed  under  the  constant  pressure  of  a  changing 
nvironment,  and  so  it  has  come  about  that  ordinarily  a 
mple  flash  of  consciousness  is  all  that  is  required  to  take 
n  any  given  situation  and  meet  it  by  making  the  proper 
eactions.1 

Range  or  Span  of  Attention. — How  many  things  can  we 
ttend  to  at  once?     Common  sense  says  that  we  can  attend 
nly  to  one  thing  at  a  time.     Careful  experiment,  however,  has 
4    roved  this  to  be  untrue.     Yet  it  is  true  that  in  every-day  ex- 
$  perience  attention  is  occupied  only  by  a  single  object  or  topic 
f  thought,  but  this  does  not  represent  the  ability  of  atten- 
on  in  this  respect,  especially  in  the  perception  of  objects, 
t  has  been  found  that  when  simple  objects  are  presented 
imultaneously  to  the  eyes,  from  Jour  to  six  single  objects 
an  be  apprehended  at  once.     If  simple  sounds  are  presented 
uccessively,  as  in  the  taps  of  a  metronome  beating  four 
imes  a  second,  six  to  eight  japs  can  be  perceived  as  a  unit 
'without  counting  the  single  taps.     In  the  case  of  the  simul- 
"^taneous  presentation  of  simple  objects  the  length  of  time  in 
xwhich  the  objects  are  exposed  to  the  eyes  must  be  very  short 
— short  enough  to  prevent  more  than  one  act  of  the  attention. 
~he  time  exposure  should  be  just  long  enough  for  the  sub- 
ject to  perceive  clearly  a  single  one  of  the  objects.     This  time 
period  varies  from  Q.OIO  to  0.200  seconds.     It  is  necessary, 
therefore,  to  use  an  accurate  time-exposure  apparatus,  called 
the    ta^histoscope,    for   these    experiments,    although    rough 
|  ^experiments  may  be  carried  on  by  means  of  an  ordinary  drop- 
;reen. 

The  result  of  experimentation  has  also  shown  that  atten- 
[ion  can  take  in  complex  objects  quite  as  easily  as  simple 

1  See  Angell:  "Psychology,"  4th  ed.,  p.  94. 


ATTENTION 


77 


objects.  For  instance,  it  was  found  that  as  many  words)] 
as  single  letters  can  be  apprehended  in  one  pulse  of  the  at-  II 
tention,  i.  e.,  three  to  six  words.  Likewise,  familiar  groups 
of  linegj  dots,or  objects  may  be  attended  to  as  a  single  im- 
pression or  uni^;  and  as  many  single  groups  can  be  perceived 
in  one  grasp  of  the  attention  as  single  objects.  This  means 
that  when  we  attend  to  the  single  group  the  attention  is  not 
occupied  with  the  single  objects  which  make  up  that  group. 
When  we  attend  to  a  word  as  such,  we  do  not  attend  to  the 
single  letters  making  up  the  word,  but  on  the  other  hand  we 
treat  the  word  as  the  unit  of  attention.  We  may  even  treat 
phrases  or  sentences  as  units  of  attention.  The  same  holds 
true  in  the  apprehension  of  successive  sounds.  Intone  pulse 
of  the  attention  some  subjects  can  perceive  four  groups_pf 
four  taps  of  the Tmetronome,  i.  e.,  sixte^n__single_^^s.  In 
this  case  the  attention  is  not  occupied  with  the  single  taps, 
but  with  the  groups.  This  illustrates  the  fact  that  an  object 
may  be  attended  to  in  different  ways.  Thus  sixteen  regular 
successive  taps  ot  the  metronome  may  be  perceived  or  at- 
tended to  as  sixteen  distinct  and  separate  sounds,  with  full  at- 
tention given  to  each  sound;  at  another  time  as  four  groups 
of  sounds,  and  at  another  time  as  a  single  group  of  four 
groups.  In  the  first  case  there  are  sixteen,  in  the  second 
four,  and  in  the  third  one  act  of  the  attention. 

This  grouping  of  objects  js  possible  because  we  build  up 
higher  and  higher  units  of  perception,  as  a  result  of  education 
and  training.  Starting  first  with  the  discrete  sensory  units, 
we  soon  learn  to  associate  them  into  groups  which  we  appre- 
hend as  single  units.  At  first  the  schoolboy  may  attend  to 
each  single  letter,  but  when  the  letters  become  associated 
attention  moves  on  to  the  word.  Thejetters  in  the  word  are 
present  in  consciousriess^_but  they  are  marginal,  i.  e.t  they 
are  not  in  the  clearest  part  of  consciousness,  for  attention  is 
occupied  with  the  word  or  higher  unit.^  Further  training 
makefe  still  higher  units  possible.  The  words  may  be  grouped 
into  phrases  and  sentences  which  are  apprehended  singly. 


5V, 


. 


PSYCHOLOGY 


Effect  of  Attention.— In  a  general  way  we  may  say  that 
attention  increases  the  efficiency  of  consciousness.  When 
the  attention  is  turned  expectantly  in  a  certain  direction 
everything  is  in  readiness  to  receive  the  stimulus,  the  end- 
organs  are  accommodated,  and  the  central  brain  centres  are 
•p_rgpared  in  advance  by  virtue__of_the  mental  image  of  the 
e^rje£ted__stimulus.  This  increases  the  rate  of  entrance  of 
the  stimulus,  and  lowers  the  sensation  thresholoL^  e.,  in- 
rrea.sesj:hfi  sensitivenp^nf  thp  nprA/nn^^nr^nkm  The  fol- 
lowing simple  experiment  will  illustrate  the  latter  point.  If 
cardboards  upon  which  geometrical  figures  (squares,  circles, 
or  triangles)  are  drawn  are  presented  to  a  subject  at  a  dis- 
tance at  which  the  figures  cannot  be  recognized,  it  will  be 
found  that,  if  the  cardboards  are  brought  slowly  nearer  to 
the  subject,  a  distance  can  be  determined  where  the  figures 
will  be  just  clearly  recognized.  Now  this  distance  will  be\^ 
greater  when  the  subject  is  told  beforehand  what  figure  is  \ 
upon  the  card  than  it  will  be  when  he  is  not  told  what  figure  K^" 
is  upon  the  card. 

The  following  table  gives  the  results  of  five  tests  under 
each  condition:  First  condition,  the  subject  did  not  know 
what  figure  was  approaching;  second  condition,  the  subject 
knew  what  figure  was  approaching. 


First  Condition 

Second  Condition 

i.  Figure  r 

2.              " 

3-          " 
4- 
5- 

Average 

^cognized  at                         ... 

i£^7  feet 
16.0   " 
i&.8   " 
15.8   " 
18.0   " 

19.9  feet 

20~f  " 

16.8   " 
23.8   " 
16.3    " 

«            « 

«            « 

it            « 

distance  recognized  

i6J5  feet 

19  .  5  feet 

Here,  when  attention  was  given  to  the  approaching  stimu- 
lus, the  distance  at  which  it  could  be  recognized  was  increased 
2.7  feet.  Likewise  the  threshold  of  auditory  sensations  is 
lowered  by  active  attention.  The  same  subject  whose  rec- 


ATTENTION  79 

ords  are  given  above  could  hear  the  ticking  of  the  laboratory 
watch  (one  he  had  never  heard  before)  only  when  it  was 
brought  within  a  distance  of  ten  feet  from  his  ear.  But  when 
he  had  once  heard  it  distinctly  and  attended  to  its  peculiar 
sound  he  could  hear  it  thirteen  feet  away. 

The  latent  period  of  perceptio^  i.  e.,  the  time  between 
the  presentation  of  the  stimulus  to  the  sense-organ  and 
recognition  of  it  in  consciousness,  is  shorter  in  attention  than 
it  is  in  marginal  consciousness,  Every  stimulus  requires 
some  time  to  develop  in  consciousness.  It  is,  of  course,  a 
relatively  short  period,  and  is  measured  in  thousandths  of  a 
second.  This  developing  period  goes  on  most  rapid|y  in  th^ 
focus  of  attention  Of  two  simultaneously  given  stimuli  the 
one  that  is  voluntarily  attended  to  arrives  in  consciousness 
first.  If  we  should  attend  closely  to  the  revolving  pointer  of 
a  complication  clock,1  and  attempt  to  locate  the  exact  posi- 
tion oFthepointeFwhen  the  bell  strikes,  we  should  find  that 
the  resulting  sound,  not  being  in  the  focus  of  attention,  will 
require  a  longer  time  to  develop  in  consciousness  than  the 
visual  appearance  of  the  pointer  on  the  dial.  Consequently 
the  sound  will  be  retarded  in  reaching  clear  consciousness. 
If,  when  the  attention  is  on  the  pointer,  the  bell  is  arranged 
to  sound  when  the  pointer  is  at  a  given  position  on  the  dial, 
the  sound  will  not  reach  consciousness  until  the  pointer  ap- 
pears to  the  observer  to  be  some  degrees  beyond.  With  the 
attention  fixed  upon  the  visual  stimulus,  the  auditory  sen- 
sation lags  behind  in  consciousness.  The  visual  sensations 
ripen  more  rapidly  than  the  auditory  sensations  under  these 
conditions,  so  that  when  the  more  slowly  developing  sound- 
sensation  reaches  consciousness,  the  visual  perception  of  the 
pointer  several  degrees  ahead  on  the  dial  has  developed  into 
clear  consciousness.  The  sound  and  the  pointer  appear 

1  The  complication  clock  is  a  graduated  dial  around  which  a  pointer  revolves 
from  six  to  ten  times  per  minute.  The  clock  is  connected,  usually  electri- 
cally, with  a  bell  which  may  be  made  to  strike  a  single  note  at  any  given  posi- 
tion of  the  pointer. 


8o  PSYCHOLOGY 

simultaneous  at  the  advanced  position  of  the  pointer,  i.  e., 
there  is  a  negative  time  displacement  of  the  sound.  If,  now, 
attention  is  fixed  upon  the  sound,  the  pointer,  being  in  the 
margin  of  consciousness,  will  lag  behind  and  will  appear  to 
be  several  degrees  back  of  the  given  position  when  the  bell 
sounds,  i.  e.,  there  is  a  positive  time  displacement  of  the 
sound. 

\        Very  common  illustrations  of  this  retardation  of  stimuli 
1  which  are  not  attended  to,  but  which  have  been  received  in 
i  marginal  consciousness,  are  found  in  every-day  life.     If  one 
is  intently  absorbed  in  reading   or  in   deep  meditation,  it 
may  happen  that  he  does  not  notice  the  striking  clock  until 
the  third  or  fourth  stroke,  and  then  become  fully  conscious 
that  he  has  heard  it  striking  from  the  beginning.     The  small 
boy  who  is  busily  engaged  in  play  probably  tells  the  truth 
when  he  says  to  his  mother,  after  she  has  called  him:  " Mother, 
I  didn't  hear  you  until  you  had  called  the  second  time." 

Attention  increases  the  speed  of  movement.  If,  when  a 
/'visual  or  auditory  signal  is  given,  a  subject  attempts  as 
quickly  as  possible  to  make  a  simple  movement,  such  as 
pressing  down  a  telegraph-key,  the  reaction  can  be  made 
more  quickly  if  attention  is  focussed  upon  the  movement  to 
be  made.  Obviously,  attention  may  be  given  either  to  the 
signal  or  to  the  movement.  If  attention  is  given  to  the 
signal,  the  time  of  reaction  is  termed  "sensory-reaction  time"; 
if,  on  the  other  hand,  attention  is  given  to  the  movement, 
it  is  "motor-reaction  time."  In  most  cases  the  "motor- 
reaction  time"  is  shorter  than  the  "sensory-reaction  time" 
by  from  0.080  to  o.ioo  seconds.  The  former  is  about  0.140, 
while  the  latter  is  about  0.240  seconds.  However,  when  the 
movement  becomes  perfectly  familiar  or  habitual,  the  differ- 
ence between  these  forms  of  reaction  tends  to  disappear.  In 
general,  we  may  say  that  the  time  of  any  conscious  reaction 
\ys  lessened  when  attention  is  given  to  the  least  familiar  or/ 
\\iabitual  elements  in  it. 

Since  attention  is  the  condition  of  all  clear  and  vivid  im- 


ATTENTION  8 1 

pressions,  its  effect  upon  memory  is  obvious.  That  which  is 
attended  to  closely  is  more  likely  to  be  retained  and  recalled 
afterward  than  that  which  is  not  attended  to.  Further- 
more, the  order  of  recall  is  determined  by  attention.  For 
what  is  remembered  depends  upon  what  is  in  the  focus  of 
attention  at  the  moment.  This  not  only  determines  the 
direction  which  the  memory  takes,  but  it  also  determines  the 
sequence  of  thoughts  in  imagination,  judgment,  and  reason — 
in  short,  in  all  consecutive  thinking. 

Motor  Accompaniments  of  Attention. — We  have  had  occa- 
sion several  times  to  refer  to  the  fact  that  attention  is  accom-  \ 
panied  by  certain  bodily  reactions.  In  fact,  the  connection 
between  the  motor  activities  of  the  body  and  attention  is  so 
intimate  and  constant  that  some  psychologists  hold  that 
attention  is  fundamentally  a  motor  phenomenon.1  The  at- 
tention we  give  in  looking  at  an  object,  according  to  this 
view,  is  really  and  essentially  nothing  more  than  the  turning 
of  the  body  toward  it,  the  accommodation  and  converging 
of  the  eyes  upon  it,  the  changed  respiratory  movements  and 
heart  action  which  take  place  when  we  attend  to  it.  Or, 
more  properly,  the  effect  of  these  motor  activities  in  con- 
sciousness is  the  only  differentia  between  attentive  conscious- 
ness and  non-attentive  consciousness.  This  theory  would 
take  the  accompaniments  of  attentive  consciousness  as  its 
cause.  Although  we  rannnt  accept,  the  theory  that  atten- 
tinn  in  rnnnntiilly  the  effect  of  a  set  of  motor  accommoda- 
tions, we  must  nevertheless  rerogpize  their  Jmportance  in 
For  no  state  of  attention  existsthat  does"  not 


show  definite  motor  adjustments  peculiar  to  it.  No  one  can 
give  attention  without  manifesting  signs  of  bodily  reactions 
toward  the  object  of  attention.  The  accommodation  of  the 
sense-organ,  the  tension  of  the  facial  muscles,  the  strained 
motor  attitude  of  the  body,  the  slowed  respiration  and  heart 
action  are  all  marks  of  attention.  It  is  doubtful  if  attention 
and  a  general  relaxation  of  the  muscles  can  take  place  at  the 

1Ribot:  "Psychologic  de  Pattention." 


82  PSYCHOLOGY 

.same  time.  These  motor  reactions  have  their  part  to 
play  in  making  the  content  of  consciousness  clear  and 
definite. 

Both  the  voluntary  and  the  involuntary  reactions  are  in- 
volved in  attention.  For  instance,  if  we  attend  to  a  visual 
object,  the  turning  of  the  head  and  eyes  toward  the  object 
and  the  partial  suspension  of  respiration  may  be  voluntary, 
but  the  adjustments  of  the  lens  and  the  pupil  of  the  eye  and 
the  capillary  change  in  the  blood-vessels  are  involuntary,  or 
reflex.  The  motor  reactions  in  attention,  therefore,  repre- 
sent  the  whole  organism,  involving  both  the  native  and  the 
acquired  reactions. 

Involuntary  movements  of  the  body  are  often  sufficiently 
observable  to  the  degree  that  they  may  be  taken  as  indica- 
tions both  of  the  direction  and  nature  of  attentive  conscious- 
ness.  Many  so-called  mind-readers  (really 


.  */> 

uy         take  advantage  of  the  involuntary  movements  of  their  sub- 
jects in   detecting   the  nature   and   direction   of   attention. 

<N   ..    Especially  is  this  true  in  cases  where  the  "mind-reader"  is 
attempting  to  find  a  hidden  article,  the  location  of  which  is 

^T-  ;>'  known  and  kept  steadily  in  mind  by  the  subject.  By  watch- 
ing the  subject  closely  or  by  holding  his  hand  as  he  leads  him 
A  about  the  room,  the  "mind-reader"  can  detect  involuntary 
movements  of  hesitation  and  negation,  of  acceptance  and 
consent,  which  give  clews  to  the  position  of  the  object.  We 
may  note  these  motor  impulses  in  ourselves.  If  we  think  of 
an  object  directly  overhead,  slight  involuntary  movements 
of  the  head  or  eyes  toward  the  object  are  observable.  If  we 
think  of  the  word  bub-ble,  movements  of  the  lips  can  be  de- 
tected. If  we  think  of  biting  into  the  pulp  of  a  raw  lemon, 
we  are  seized  with  involuntary  shudders.  Such  move- 
ments are  usually  not  noticed  until  attention  is  called  to 
them. 

Now,  if  we  canvass  all  the  movements  that  characterize 
attention  we  shall  find  that  they  fall  into  four  classes  :  l 
^ee  Pillsbury:  "Attention,"  chap.  II. 


ATTENTION  83 

First:  Movements  of  accommodation  of  the  sense-organs, 
fhe  purpose  pf  ^Hph  is  to  give  a  clearer  impression  of 
stimuli.1  \f*x~*^j£5**^  ^.  VvvvVjU^<M*x 

~  Second:  Movements  of  the  voluntary  muscles,  expressly 
made  for  the  purpose  of  taking  advantage  of  the  objects  or 
ideas  attended  to  in  a  way  that  has  previously  been  found 
useful  to  the  organism.  ~w\  ^  ljj^\  t> 

Third,:    Overflow  movements  in  the  voluntary  muscles.2 

Fourth  :  Reactions  of  the  respiratory  and  circulatory  mus- 
cles. The  pulse  and  respiration  curves  show  marked  changes 
with  the  changing  states  of  attention.  The  blood-pressure  in 
the  capillaries  also  varies  with  the  attention  changes. 

These  motor  accompaniments  are  present  not  only  in 
sensory   attention    (attention    to   objects   presented    to    the 
senses),  but,  as  we  have  already  seen,  they  are  also  found  in 
intellectual  or  ideational  attention,  attention  given  to  mem- 
ories, images,  and  ideas.     The  memory  image  of  a  green  per- 
simmon will  cause  the  same  puckering  of  the  mouth,  although 
perhaps  in  a  lessened  degree,  which  the  fruit  itself  caused 
when  actually  experienced.     To  form  the  mental  image  of 
an  object  behind  us  involves  the  tendency  to  turn  the  head. 
The  idea  of  coldness  is  accompanied  with  incipient  shivers. 
\VIn  short,  all  our  clear  and  vivid  thoughts  are  accompanied  jj 
^4by  motor  reactions  that  are  more  or  less  appropriate  to  them.  » 
»Put  in  a  way  which  will  cover  the  facts  of  both  sensory  and 
ideational  attention,  we  may  say  that  all  clear 
g  motor 


Feeling  of  Effort  in  Attention.  —  The  fact  that  we  experi- 
ence  effort  and  strain  in  voluntary  attention  leads  naturally 

1  This  should  include  the  movements  of  the  body  which  place  the  sense- 
organs  in  a  more  advantageous  position  with  respect  to  the  stimulus.     These 
movements  may  be  voluntary  and  so  differ  from  the  involuntary  accommoda- 
tions of  the  sense-organs,  but  their  purpose  is  the  same,  i.  e.,  to  give  a  clearer 
impression  of  the  stimulus. 

2  It  has  been  suggested  that  these  overflow  movements  serve  to  keep  the 
neural  activity  going  in  the  same  channel  and  thus  inhibit  the  effect  of  dis- 
turbing stimuli.     See  Angell:  "Psychology,"  4th  ed.,  p.  101. 


84  PSYCHOLOGY 

to  the  assumption  of  an  activity  back  of  the  contents  of 
the  attention-consciousness — a  something  that  decides  what 
things  are  to  be  attended  to.  Effort  and  strain  are  assumed 
to  be  the  effort  and  strain  of  the  attention  itself.  Now,  care- 
ful observation  reveals  the  fact  that  the  effort  and  strain 
come  from  the  motor  accompaniments  of  attention,  and  not 
from  attention  itself.  The  contracted  brow,  the  set  teeth, 
and  other  bodily  muscular  tensions,  together  with  the  adjust- 
ments of  the  sense-organs,  give  a  diffused  mass  of  strain- 
sensations.  They  might  very  readily  be  taken  in  superficial 
observation  for  the  activity  of  the  attention. 

Interest  and  Attention. — Popular  thought  has  some  very 
decided  views  concerning  the  relation  of  interest  to  attention. 
For  instance,  it  is  supposed  that  interest  precedes  and  leads 
to  attention — that  we  attend  because  we  are  interested,  not 
that  we  are  interested  because  we  attend.  While  this  view 
contains  an  element  of  truth,  it  involves  a  confusion  of 
thought  that  may  be  easily  corrected  if  we  consider  what 
interest  really  includes  psychologically. 

In  the  first  place,  interest,  as  we  commonly  use  the  term, 
includes  attention.     We  cannot  be  interested  without  attend- 
ing.    Interest,  therefore,  cannot  exist  and  then  attract  atten- 
tion to  it  afterward,  for  the  very  reason  that  any  state  of 
consciousness  that  may  be  called  interest  has  attention  al- 
ready in  it.     Interest  is  a  complex  mental  state  comprised  || 
of  a.  Hear  and  vivid  state  i  f  awareness  (attention),  accom-il 
panjed  ^y  feeling  and  conation  (impulse      ^activity") .  ""when  »\ 
we  are  interested  we  are  clearly  aware  of  the  object  of  inter- 
est, take  a  feeling  attitude  toward  it,  and  are  impelled  to 
react  in  some  way,  /.  e.,  approach  or  withdraw  from  the 
object. 

(  Vivid  awareness  (attention). 
Interest  -I   Feeling. 
[  Conation. 

The  most  important  element  in  this  complex  is  attention. 


ATTENTION  85 


JJQ_  real  separation,  nf 


In  fact,  interest  is  only  another  name  for  non-voluntary  or 
spontaneous  (both  native  and  acquired)  attention.  The 
things  that  we  are  interested  in  are  the  things  that  attract 
the  spontaneous  attention.  Moreover,  the  order  of  the  de- 
velopment of  our  interests  is  the  order  of  development  of 
attention.  First  come  our  native  interests  —  food,  shelter, 
intense  stimulation,  bright  lights,  loud  sounds,  moving  things, 
etc.,  and  last  of  all,  our  acquired  interests  —  art,  literature, 
science,  our  professions,  occupations,  etc.  Between  the  na- 
tive and  acquired  interests  lies  the  stage  of  voluntary  atten- 
tion. Our  acquired  interests  rest  mainly  in  those  things 
with  which  we  have  become  familiar  through  voluntary 
attention. 

Sometimes  interest  is  used  to  signify  only  the  affective 
elements  in  attention  —  the  feeling  of  pleasure  and  satisfaction 
experienced  with  our  states  of  awareness.     We  get  pleasure  \\ 
and  satisfaction  out  of  the  things  that  help  us  forward,  and  '• 
therefore  we  attend  to  these  things.     It  is  better  to  say  that 
we  get  pleasure  and  satisfaction  because  we  attend,  for  the 
pleasure  and  satisfaction  are  never  experienced  qntil  after 
attention  is  given,.^  If  we  go  in  quest  of  these  interesting 
things,  we  must  first  attend  to  the  memory  images  of  them 
before  our  interest  is  awakened. 

From  the  genetic  point  of  view  interest  follows  attention; 
for  it  is  -not  until  after  the  organism  gets  a  clear  and  definite 
awareness\of  the  objects  in  its  environment  that  it  takes  the 
attitude  of^  interest  toward  them.  Now,  in  the  evolutionj>f 
consciousness  some  states  of  awareness  were  accompanied  by 
more  feeling  and  more  conation  than  others.  These  states 
of  vivid  awareness,  with  their  accompaniments  of  feeling  and 
conation,  were  the  primitive  states  of  interest.  Certain 
things  attracted  attention,  aroused  feeling,  and  impelled  to 
action.  They  were  the  things  that  were  vitally  beneficial 
or  harmful  to  the  organism.  That  is  the  reason  they  com- 
manded the  attention,  and  also  the  reason  they  became  in- 


86  PSYCHOLOGY 

teresting  when  attention  was  given.  And  so  we  have  come 
to  call  the  things  interesting  that  we  attend  to  spontaneously. 
We  should  not,  however,  forget  that  attention  has  created 
the  interest. 


CHAPTER  IV 
SENSATION 

Sensation  as  an  Element  of  Consciousness. — When  we 
examine  our  consciousness  of  the  external  world  we  find  that 
it  is  very  complex.  Even  the  simplest  thing  has  a  large 
number  of  qualities.  The  rose  has  color,  fragrance,  form, 
and  thorns,  all  of  which  may  assail  the  different  senses  at 
the  same  time  and  are  therefore  present  in  our  consciousness 
of  it.  We  are  never  conscious  of  any  one  of  these  qualities 
alone.  They  ajwa^s^exjs^jn^^TOn^ination.  It  is  the  busi- 
ness of  psychology  to  analyze  these  complex  experiences  of 
the  external  world  into  their  simplest  elements,  and  to  take 
account  of  them  separately. L o~"***j  3t>  '**£^-  «~~>*-»'»ti~ujr~a^ 

The  simplest  elements  into  which  we  can  analyze  our 
cognitive  consciousness  are  sensations.  Such  experiences  as 
color,  smell,  pressure,  pain,  and  taste,  which  we,  as  psycholo- 
gists, abstract  from  the  larger  conscious  states  in  which  we 
find  them,  and  which  we  are  unable  to  analyze  into  still  sim- 
pler experiences,  are  sensations.  If,  for  instance,  we  could 
attend  to  the  redness  of  the  rose  alone,  the  color,  abstracted 
from  the  form  and  material  of  the  petals,  from  its  relation 
to  surrounding  objects,  from  its  position  in  space,  from  its 
unlikeness  to  the  green  leaves,  would  be  a  simple  sensation. 
Sensations,then ,  are  the  immediate  and  unanalyzable  ele- 
lnen^_of_cogmtive  consoousness\_  Or,  as  Professor  James 
^puts  it,  "Sensation  is  the  immediate  result  of  stimulations 
before  further  knowledge  or  past  experiences  are  awakened. 
Sensation  is  the  basis  of  all  knowledge.  A  being  without 
sense-organs  of  any  kind  could  never  know  anything  of  the 
world  about  him." 

87 


88  PSYCHOLOGY 

Pure  Sensations. — It  is  evident  that  "pure  sensations  " 
are  psychological  abstractions,  the  result  of  psychological 
analysis.  They  are  never  realized  in  actual  experience.  It 
is  said  that -pure  sensations  are  possible  only  during  the  very 
first  experiences  of  childhood.  Afterward  stimuli  arouse 
more  than  the  sensations  themselves.  Past  experie'nces,  sug- 
gestions of  familiarity,  relations  of  likeness  and  unlikeness, 
meanings,  all  these  and  more  come  along  with  sensations. 
However,  it  is  necessary  in  our  study  to  abstract  sensations 
from  the  complexes  hi  which  they  appear,  and  treat  them  as 
though  they  existed  independently  of  the  combinations  in 
which  they  are  manifest.  For  example,  the  rose  arouses  not 
only  the  sensation  of  red,  but  also  awareness  of  its  position  in 
space,  consciousness  of  familiarity,  and  many  other  factors 
which  involve  revived  past  experiences.  Just  the  sensation 
redness  cannot  exist  alone.  However,  at  times,  we  may 
have  sense-experiences  which  approach  the  simple  quality  of 
pure  sensations.  If  some  one  should  explode  a  giant  fire- 
cracker under  my  chair  quite  unexpectedly,  the  very  first 
brief  instant  of  sense-impression  I  receive,  before  collecting 
myself  sufficiently  to  have  any  suggestion  as  to  the  nature 
or  position  of  the  disturbance,  would  approximate  a  pure 
sensation.  Immediately,  however,  as  past  experiences  re- 
vive and  mental  syntheses  begin  to  form,  recognition  both 
of  the  nature  and  the  position  of  the  disturbance  would  join 
with  the  simple  sensation,  making  it  a  complex  experience. 

In  view  of  this  fact  it  is  evident  that  ordinary  observation 
of  mental  life  must  be  supplemented  by  scientific  treatment. 
Unless  we  consider  sensation  as  simple  and  elementary  and 
capable  of  being  isolated  for  purposes  of  stud)'",  no  scientific 
analysis  of  our  sensory  experiences  can  take  place. 

Physiological  Basis  of  Sensation. — In  all  parts  of  the 
body,  there  are  sensory  surfaces  supplied  with  sense-organs, 
which  are  connected  by  nerve-fibres  with  the  sense  centres 
in  the  brain.  .The  vital  organs,  the  articular  surfaces,  the 
muscle  and  tendon  bundles,  the  skin,  the  mouth,  the  tongue, 


SENSATION  89 

and  the  nasal  cavities,  the  ear,  the  retinal  surface  of  the  eye 
— all  have  their  own  specific  sensory  nerve-endings  which 
connect  through  chains  of  nerve-fibres  with  the  brain.  Some 
of  these  sense  end-organs  are  affected  primarily  by  conditions 
existing  within  the  body,  while  the  others  are  affected  by 
objects  outside  the  body.  Whatever  affects  the  sensory  end- 
organs  sets  up  nerve-impulses  which  are  transmitted  to  the 
brain.  Nerve -tissue  possesses  a  characteristic^  _jmown  as 
irritability  of  nervous  tissue^  "By  virtue  of  which  changes  in  .- J^*^ 
one  part  of  it  arecommunicjie^tc^jitliexjQaTt^.  The  sen-  »F 
sory  end-organs,  connected  as  they  are  with  the  brain,  form  a 
rather  extended  system  of  reporting  agencies  which  keep  the 
central  nervous  system  in  touch  with  the  happenings  that 
are  constantly  taking  place  in  the  body  and  in  the  world  of 
objects  outside. 

The  Nature  of  the  Nerve-Impulse. — Just  what  happens  in 
a  nerve  that  has  been  stimulated  and  is  transmitting  impulses 
the  physiologist  is  at  present  unable  to  say.     It  is,  however,  toy 
certain  that  some  form  of  energy  is  set  up  in  the  sense-organs  v_ 
by_the__action  of  the  stimuli.     This  energy  is  then  trans- 
mitted over  the  nerve-fibres.     There  is,  however,  no  means  »ij 
of  deciding  whether  its  nature  is  mechanical,  chemical,  or  !' 
electrical.     An  interesting  question  arises  as  to  whether  the 
nerve-impulses  in  the  nerve^fibres 


are_the^s5me_in_ciuality^or  whether  thesejibres  carry  differ^ 
ent  specific  energies  to  the  brain.     No  matter  how  the  optic  ML 
nerve  is  stimulated,  either  by  the  light  falling  upon  the  ^ye 
or  by  an  electric  current  passing  through  the  forehead,  or 
by  a  blow  upon  the  head,  or  by  pressing  upon  the  eyeballs, 
the  result  is  a  sensation  of  light.     Similarly,  each  sensory  ' 
nerve,  however  stimulated.  Drives  rise  to  its  own  appropriate 
sensation  when  its  impulse  reaches  the^bram  centre.     We  \ 
may  interpret  these  facts  in  two  ways:   Wittier  eaciTkind  of  \ 
sensory  nerve  carries  different  impulses,  or  all  sensory  nerves    ] 
carry  the  same  kind  of  nerve-impulses.     In  the  latter  case  J 
the  different  forms  of  sensation  which  they  arouse  are  due 


90  PSYCHOLOGY 

not  to  the  impulses  in  the  nerves  themselves,  but  to  the  ac- 
tivities in  the  different  brain  centres.     The  first  alternative 
is  known  as  the  theory  of  the  specific  energy  of  nerves.     Mod- 
ern physiologists  are  inclined  to  deny  this  theory.     They 
hold  that  the  "specific  quality"  belongs  not  to  the  periph- 
eral nerve-impulses,  but  rather  to  the  central  brain  processes. 
There  is  no  physiological  evidence  of  specific  energies  in  dif- 
ferent sensory  fibres.     So  far  as  we  know,  there  is  no  differ- 
ence in  kind  between,  for  example,  the  impulses  in  the  optic 
nerve  and  the  impulses  in  the  auditory  nerve.     On  the  other 
hand,  it  seems  more  reasonable  to  suppose  that  each  sense- 
organ  has  a  different  mode  of  nervous  action,  and  that  its 
iv  specific  mode  of  action  is  transmitted  to  the  brain  by  its 
^nerve-fibres.     However,  in  the  present  state  of  physiological 
W"  knowledge,  the  question  cannot  be  definitely  answered. 
,         Evolution  of  Sense-Organs. — There  are  some  reasons  for 
v  believing  that  the  highly  developed  special  sense-organs  are 
the  result  of  evolution — that  they  have  developed   in   the 
course  of  racial  growth  from  the  primitive  sensitive  epithelial 
cells  in  the  skin.     In  man  the  tactile  sense  is  the  nearest  ap- 
proach to  the  primitive  epithelial  sense  in  the  lowest  animal 
forms.     The  skin,  or  epithelium,  is  probably  the  earliest  sense- 
organ.     When,  in  the  racial  series,  the  differentiation  from 
this  primitive  general  sense  toward  the  special  senses  began, 
it  originated  in  a  modification  of  the  epithelial  cells.     These 
cells  became  elongated,  with  their  peripheral  ends  turned 
toward  the  surface  for  the  reception  of  the  stimuli.     From 
the  other  ends  nerve-fibres  were  developed  for  transmitting 
impulses  to  other  parts  of  the  organism.     Thus  the  sense- 
organs  of  smell,  taste,  and  pressure  were  developed.     Even 
.    in  the  cases  where  the  sense-organs  do  not  lie  on  the  surface 
^j    of  the  body,  as  in  sight  and  hearing,  the  sensitive  cells  are 
X    developed  from  the  epithelium.     The  auditory  sense-organ 
*Ov  of  the  higher  animal  forms  may  be  traced  back  to  an  open 
auditory  pit,  like  that  of  the  crawfish.     A  higher  form  of  the 
auditory  pit  is  the  auditory  vesicle  of  the  mollusk.    Here 


SENSATION  91 

the  auditory  vesicle  bears  upon  its  surface  sensitive  epithelial 
cells  which  are  centrally  connected.  Within  the  vesicle  is  an 
auditory  ossicle  held  in  place  by  hair-like  cells.  In  the  ver- 
tebrates the  auditory  vesicle  has  developed  into  the  sacculus 
and  the  utricuius  of  the  ear.  From  the  sacculus  there  has 
developed  a  spirally  wound  tube,  the  cochlea,  while  from  the 
utricuius  have  grown  the  semicircular  canals  in  the  ear  of 
man. 

The  sense-organ  of  vision  has  likewise  undergone  many 
transitional  stages  of  development.  The  simplest  form  con- 
sists of  a  group  of  pigmented  cells  lining  the  walls  of  a  de- 
pression in  the  skin.  These  cells  are  elongated,  with  one 
end  turned  toward  the  light  and  the  other  end  drawn  out 
in  order  to  make  proper  nerve  connections.  Such  a  primi- 
tive eye  is  found  on  the  jentacles  ofthe  limpet.  A  further 
development  of  simple  eye-spots  is  found  in  some  species  of 
worms,  where  a  light -concentrating  apparatus  has  been 
evolved.  The  snail  shows  a  still  higher  form.  Here  a 
simple  retina  with  a  protecting  covering  and  a  lens  for 
focussing  light-rays  appear.  The  lens,  however,  is  not  suffi- 
ciently developed  for  forming  images,  so  that  the  snail  does 
not  possess  distinct  vision.  The  next  step  is  the  perfecting 
of  the  lens,  and  where  this  has  taken  place  there  is  close  ap- 
proximation to  the  eye  of  man. 

In  the  tactile  sense  there  has  been  a  development  from  a 
sensitive  epithelial  cell  provided  with  a  hair  shaft  so  placed 
that  movement  of  the  hair  is  communicated  to  the  cell,  to 
the  tactual  corpuscles  of  Meissner,  a  bulb-like  formation  of 
nerve-fibres  found  in  tne  sRin  oi  man.  The  end-organs  of 
cold  and  warmth  have  also  been  differentiated  from  the 
primitive  tactile  cells. 

The  Stimuli. — A  stimulus  is  any  force  that  acts  upon  a, 
sense-organ^  The  forces  which  Inake  up  the  various  stimuli 
usually  come  from  objects  outside  of  the  organism,  but  in 
certain  cases  they  arise  within  the  organism  itself.  Physio- 
logical changes  may  liberate  forces  which  act  upon  sense- 


organs  and  give  rise  to  sensations.     Most  of  the  organic  sen 

k  sations  are  set  up  in  this  way.     Hunger,  thirst,  organic  pain, 

etc.,  are  caused  by  physiological  changes  within  the  organism. 

The  stimuli  which  affect  the  end-organs  are  innumerable, 

but  they  may  be  classified  roughly  into  the  following  groups : 

1 .  Mechanical  stimuli.  — 

2.  -Chemical  stimuli.  - 

3.  Thermal  stimuli.  - 

4.  Photic  stimuli.  - 

5.  Electrical  stimuli.  - 

Mechanical  stimuli  consist  in  changes  of  pressure,  such  as 
those  caused  by  objects  coming  in  contact  with  the  skin  sur- 
faces, or  sound-vibrations  beating  against  the  ear.  Chemical 
stimuli  come  from  the  chemical  changes  going  on  in  food  sub- 
stances taken  into  the  mouth,  and  possibly  in  odorous  par- 
ticles or  in  gases  affecting  the  nose.  Thermal  stimuli  are 
changes  in  the  temperature  surrounding  the  organism.  Photic 
stimuli  are  light-vibrations  (supposed  to  be  ether-vibrations) 
affecting  the  eye.  Electrical  stimuli  seem  to  be  able  to  affect 
most,  if  not  all,  of  the  sense-organs. 

/•  With  respect  to  their  appropriateness  or  fitness  to  affect 
sense-organs,  we  may  divide  stimuli  into  adequate  and  inade- 
quate stimuli.  Adequate  stimuli  are  those  to  which  the  sense- 
organs  are  fully  adapted,  while  inadequate  stimuli  are  those 
to  which  the  sense-organs  are  not  adapted.  Light  is  an  ade- 
quate stimulus  for  the  eye;  air-vibrations  for  the  ear;  warmth, 
cold,  and  pressure  for  the  skin;  soluble  substances  for  the 
taste  sense-organs,  and  gaseous  particles  for  the  smell  sense- 
organs.  On  the  other  hand,  light  does  not  affect  the  ear  nor 
air-vibrations  the  eye.  They  are  therefore  inadequate  stimuli 
in  these  cases.  While  a  blow  on  the  head  or  pressure  on  the 
eye  may  result  in  light-sensations,  such  stimuli  are,  neverthe- 
less, inadequate  stimuli  for  the  eye.  In  so  far  as  a  sense- 

jj  organ  is  affected  by  inadequate  stimuli,  it  gives  rise  to  its 

M  own  specific  sensation. 

What  the  real  stimulus  is  is  a  question  which  transcends 


SENSATION 

the  limits  of  naive  thinking.  Ordinarily  we  are  in  the  habit 
of  considering  the  object  we  experience  as  the  stimulus.  But 
careful  consideration  will  show  us  the  error  of  this  way  of 
thinking.  \ye  are  never  conscious  of  the  stimulus  itself, 
Light-sensations  are  the  result  of  the  vibrations  of  some  form 
of  energy  (supposed  to  be  ether)  which  acts  upon  the  rods 
and  cones  of  the  retina.  Sound- sensations  are  set  up  by  air- 
waves falling  upon  the  sensitive  parts  of  the  ear.  But  we  are 
never  directly  conscious  either  of  the  air-waves  or  of  the  ether- 
vibrations  themselves.  So,  through  all  the  senses,  the  real 
stimuli  that  affect  the  sense-organs  and  set  up  sensory  ex- 
periences are  always  beyond  our  direct  observation,  and  so 
are  never  experienced  themselves.  We  can  only  infer  their 
nature.  What  these  various  forms  of  energy  in  the  mechan- 
ical, chemical,  thermal,  photic,  and  electrical  stimuli  are  is 
a  problem  for  physics  to  solve.  This  consideration  naturally 
raises  the  question  of  the  nature  of  the  objects  which  we 
experience.  Physically,  of  course,  we  say  that  they  are  dif- 
ferent forms  of  energy.  But  are  they  really  what  our  expe-  / 
rience  reports  them  to  be?  Do  they  exist  as  we  experience  J 
them,  or  are  they  something  entirely  different?  Or  do  they  I 
exist  only  as  our  experience  ?  Really,  psychology  is  interested  I 
in  and  capable  of  deciding  upon  only  one  point  raised  in  these 
questions.  And  that  is  that,  whatever  else  the  so-called  ob- 
ject in  the  outer  world  is,  it  is  at  least  mv  experience^ 

A  still  more  complex  situation  confronts  us  when  we  con- 
sider that  between  the  stimulus  and  the  sensation  there 
stands  another  form  of  objective  existence  (the  nervous  proc- 
ess in  the  brain),  of  which  we  are  not  conscious.  We  cannot 
sense  the  brain  processes,  for  the  brain  is  insensitive  to  its 
QWJI  activities^  Here,  again,  we  see  that  sensation  depends 
upon  something  (the  brain  process)  that  is  itself  beyond  our 
direct  observation.  Some  curious  theories  have  been  ad- 
vanced to  explain  how  a  material  object  is  presented  to  con- 
sciousness. For  instance,  some  of  the  earlier  philosophers 
supposed  that  objects  give  off  a  kind  of  spiritual  essence,  or 


94  PSYCHOLOGY 

copy,  which  enters  consciousness,  and  in  this  way  objects 
reveal  themselves  to  us.  But  we  have  overstepped  the  limits 
of  psychology  and  are  in  the  field  of  metaphysics. 
X  After-Effects  of  Stimulus. — The  length  of  time  whjda  a 
stimulus  acts  upon  the  end-organ  and  the  duration  of^the 
resulting  sensation  ,are  not  the  same.  With  respect  to  the 
stimulus,  the  sensation  is  retarded.  Sensation  does  not  start 
the  instant  the  stimulus  begins  to  act  upon  the  sense-organ. 
This  is  due  to  the  inertia  of  the  nervous  mechanism.  A  brief 
period  is  required  to  set  the  neural  machinery  in  action. 
Even  after  the  sensation  begins  it  does  not  reach  its  maximum 
at  once.  This  fact  cannot  be  observed  directly,  but  can  be 
demonstrated  in  the  laboratory.  If  a  light  of  a  given  inten- 
sity is  allowed  to  act  upon  the  eye  intermittently,  so  that 
each  period  of  stimulation  is  very  brief,  the  resulting  sensa- 
tion, although  constant,  is  reduced  in  brightness,  due  to  the 
fact  that  the  stimulus  acts  for  so  short  a  time  that  the  neural 
process  is  not  raised  to  its  maximum  intensity. 

In  addition  to  the  initial  retardation  of  sensation,  there 
is  another  discrepancy  between  the  time  of  the  stimulus  and 
that  of  the  sensation,  namely,  that  the  sensation  continues 
for  some  time  after  the  stimulus  ceases  to  act  on  the  end- 
organs.  This  finds  its  explanation  in  the  fact  that  the  ac- 
tivity of  the  end-organs  continues  after  the  stimulus  is  re- 
moved. Every  child  is  familiar  with  the  phenomenon  of  the 
continuous  circle  of  fire  caused  by  rapidly  whirling  a  glowing 
ember.  The  retinal  process  in  each  part  of  the  eye  stimu- 
lated continues  to  act  until  the  stimulus  reaches  that  part 
again,  giving  the  appearance  of  a  continuous  stimulus.  A 
convenient  way  of  demonstrating  the  continuance  of  sensa- 
tion after  the  removal  of  the  stimulus  is  to  look  steadily  at 
the  glowing  wires  of  an  electric-light  bulb  and  then  turn  off 
the  light,  leaving  the  room  dark.  The  sensation  which  is 
caused  by  the  illuminated  wires  will  continue  for  a  time  and 
may  be  projected  to  any  part  of  the  room.  Blink  the  eyes 
and  it  stands  out  more  clearly;  close  the  eyes  and  the  light 


SENSATION  95 

may  be  seen  located  within  the  darkened  field.  The  after- 
effects of  stimulation  are  equally  prominent  in  the  cutaneous 
sensations.  Touch  the  back  of  the  hand  with  the  point  of  a 
pencil  and  notice  the  after-sensation  when  the  pencil  is  re- 
moved. 

These  after-sensations  are  commonly  called  "after- 
images," which  term  has  been  applied  mostly  to  the  visual 
sensations.  Under  some  conditions  the  after-effects  of  the 
visual  stimulus  is  the  opposite  of  the  primary  sensation.  If 
the  after-sensation  of  the  glowing  electric-light  filaments  is 
watched  with  the  eyes  closed,  it  will  presently  change  to  an 
intense  black  projected  against  the  dark  field  of  the  closed 
eyes.  If  the  eyes  are  opened,  it  may  be  projected  upon  a 
white  background  as  a  dark  image.  If,  after  gazing  at  a 
bright  window  from  a  darkened  part  of  the  room,  the  eyes 
are  tightly  closed,  a  picture  of  the  window  will  be  seen  in  the 
retinal  field,  but  the  distribution  of  light  and  dark  parts  will 
be  reversed.  The  sashes  will  appear  light  and  the  panes  dark. 
If  the  eyes  are  not  closed,  the  image  of  the  window  may  be 
projected  upon  any  white  background.  Here,  as  before,  the 
light  and  shade  are  reversed.  The  after-effect  of  color- 
stimulation  is  seen  in  the  complementary  hue  of  the  primary 
sensation.  If-  after  fixating  a  yellow  cross  on  a  blue  back- 
ground for  half  a  minute,  one  looks  at  a  neutral  gray  surface, 
the  cross  will  appear  in  a  bluish  tone  upon  a  yellowish 
background.  Such  after-effects  have  been  called  "negative 
after-images,"  in  contradistinction  to  the  after-sensations 
whicrT  preserve  the  same  qualities  as  the  primary  sensa- 
tions, and  which  have  received  the  name  of  "  gositiveafier- 
images." 

"  AiT1  interesting  effect  due  to  negative  after-images  may  be 
gotten  by  looking  steadily  at  the  dot  in  the  centre  of  the 
circle  in  Figure  37  for  forty  seconds,  and  then  quickly  fixating 
the  central  part  of  a  sheet  of  white  paper.  If  the  after-image 
does  not  stand  out  clearly,  blink  the  eyes  rapidly  several 
times,  still  fixating  the  white  paper. 


PSYCHOLOGY 

engory  Adaptation. — -After  a  stimylus  has  acted  for  some 
time  japon^  a  sense-organ  the  resulting  sensation  is  less  fully 
experienced  than  it  was  at  first^  This  lessening  of  the  in- 
tensity of  sensory  impressions,  which  is  due  to  the  continued 
action  of  the  stimulus,  is  known  as  sensory  adaptation.  Sen- 
sory adaptation  shows  itself  most  in  frbp  dpnsp  of  ^mpl]  and 


least  in  the  sense  of  p.am.  Odors 
fade  out  very  rapidly  if  they  are 
continuously  present  to  the  sense- 
organs.  Pain,  on  the  other  hand, 
loses  very  little  of  its  intensity  as 
we  continue  to  experience  it.  All 
the  other  senses,  however,  show 
sensory  adaptation.  The  pressure 
of  glasses  upon  the  bridge  of  the 
nose  is  felt  quite  distinctly  when 
they  are  first  put  on,  but  after 
they  are  worn  for  a  while  the 
pressure  becomes  unnoticeable.  A  cold  bath  seems  relatively 
less  cold  after  the  first  plunge.  A  room  which  seems  very 
brightly  illuminated  when  we  first  enter  it  appears  less 
bright  after  the  first  few  minutes.  We  soon  become  accus- 
tomed to  the  sound  of  the  ticking  clock  and  fail  to  hear  it. 
Attempts  have  been  made  to  explain  sensoryadapjbation  by 
referring  it  to  fatigue  in  the  sense-organs^^^n^niebrain_ 
"WKile  fatigue  ol 


FIG.  37. 


tfesT 


ex- 


%^     ^ 

plain  many  cases  of  sensory  adaptation,  there  may  be  other 
factors  entering  into  the  phenomenon. 

Curiously  enough,  the  term  "adaptation"  has  another 
meaning  in  psychology.  It  is  used  to  denote  the  increase  of 
visual  sensitivity  in  faint  and  bright  illumination.  On  going 
from  broad  daylight  into  a  darkened  room,  we  are  at  first 
unable  to  distinguish  objects  clearly,  but  after  a  few  minutes 
our  ability  to  see  increases.  The  eyes  become  accustomed  to 
the  faint  illumination,  or,  as  we  say,  they  become  dark- 
adapted.  The  same  thing  takes  place  when  we  go  from  a 


SENSATION  •    97 

dark  room  into  the  broad  daylight.  At  first  the  light  is  too 
strong.  Not  until  we  become  accustomed  to  it  are  we  able 
to  see  clearly.  In  this  case  the  eyes  become  light-adapted. 
The  student  will  have  to  determine  from  the  context  which 
of  the  two  meanings  is  intended  when  the  term  "adaptation" 
is  used. 

Attributes  of  Sensation.  —  All  sensations  possess  certain 
essential  characteristics.  The  four  most  important  are: 

1.  Quality. 

2.  Intensity. 

3.  Extensity. 

4.  Duration. 

These  characteristics  do  not  reveal  themselves  to  observation 
as  being  essential  aspects  of  sensation  in  the  same  degree. 
For  instance,  it  is  plain  that  all  sensations  possess  quality, 
intensity,  and  duration.  But  the  case  is  not  so  clear  for 
extensity.  Auditory,  gustatory,  olfactory,  and  some  of  the 
organic  sensations  are  thought  by  some  psychologists  not  to 
have  this  attribute.  It  must  be  admitted  that,  if  it  is  present 
in  these  sensations,  it  plays  a  more  obscure  part  than  the 
other  attributes.  We  shall  discuss  the  matter  later. 

Quality.  —  Quality  is  the  unique  and  unanalyzable  char- 
acteristic which  gives  sensations  their  psychic  nature  and 
marks  them  off  into  distinct  mental  existences.  Any  ob^. 


s,ervable_change_in  quality  gives  a  new  sensation.  Psycho- 
logically, it  is  the  most  fundamental  thing  in  sensory  experi- 
ence. The  sensation  red  is  qualitatively  different  from  the 
sensation  blue.  Bitter  is  different  from  sweet,  pressure  from 
pain.  We  may  consider  that  all  sensations  of  red  have  the 
same  psychic  quality.  All  groups  of  sensations  which  show 
the  same  intimate  sameness  of  experience  may  be  thought  of 
as  having  the  same  quality.  Taste-sensations  exist  in  four 
different  qualities:  sweet^,  sour,  salt,  and  biitejr;  color-sensa- 
tions also  in  four:  red,  yellow,  green,  and  blue,  each  forming 
a  single  quality. 

When  we  consider  the  whole  field  of  sensations,  we  find 


98  PSYCHOLOGY 

that  it  falls  apart  into  larger  groups,  or  modes,  and  in  such 
a^  way^  that  the  diflerences^bgtween  the  modes  is  markedly 
greater~than  the__differeaces__between  the  groups  within  the 
mooles^  All  the  visual  sensations  make  up  a  single  mode, 
fEe  auditory  sensations  another,  the  gustatory  sensations 
another,  and  so  on.  There  is  a  decided  break  in  the  quality 
of  the  sensations  when  passing  from  one  mode  to  another, 
as,  for  instance,  when  we  pass  from  a  sensation  of  taste  to  a 
sensation  of  color.  Such  a  difference  we  may  call  a  differ- 
ence in  modality.  On  the  other  hand,  within  a  single  mode 
we  may  pass  from  one  group  of  sensations  to  another  through 
a  gradation  of  qualitative  changes  so  slight  that  they  escape 
observation,  thus  making  the  qualities  appear  to  exist  in  a 
continuous  series.  Such  a  series  is  illustrated  by  the  tonal 
qualities,  where  we  may  go  from  the  lowest  bass  note  to  the 
highest  treble  along  a  single  line  of  qualitative  changes  with- 
out a  break.  The  visual  sensations  form  another  (although 
much  more  complex)  system  of  sensation-qualities.  The  dif- 
ferences within  these  systems  may  be  called  differences  of 
quality. 

Although  there  is  as  yet  no  definite  physiological  evidence 
to  settle  the  matter,  we  may  suppose  that  the  physiological 
basis  for  the  quality  of  a  sensation  is  to  be  found  in  the  spe- 
cific kind  of  nerve-activity  aroused  in  the  brain  centres  by 
the  action  of  a  specific  kind  of  sense-organ.1  Differences  of 
modality  in  sensations  are  based  upon  the  activity  of  differ- 
ent areas  or  centres  in  the  cortex  of  the  brain.  Thus  the 
visual  sensations  have  their  seat  in  the  occipital  lobes,  while 
the  auditory  sensations  have  theirs  in  the  temporal  lobes. 

Intensity. — Every  sensation  possesses  some  degree  of  in- 
tensity. The  same  sensation,  without  changing  its  quality, 
may  vary  in  intensity  from  the  weakest  to  the  strongest.  A 
sound  may  be  soft  or  loud,  a  pressure-sensation  may  be  light 
or  heavy,  and  so  sensations  vary  in  intensity.  We  may  sup- 
pose that  the  intensity  of  sensation  depends  upon  the  inten- 
1  See  discussion  of  the  "Physiological  Basis  of  Sensations,"  p.  88. 


SENSATION  99 

sity  of  the  neural  activity  in  the  sense-organs  and  the  brain, 
and  that  the  intensity  of  the  neural  activity  is  determined  by 
the  intensity  of  the  stimulus.  Theriiis^Jthen^.anin.direcLr.ela- 
tion  between  -the  intensity  of  the  stimulus  and  the  intensity 
of  sensation.  Within  certain  limits,  the  more  intense  the 
stimulus  the  more  intense  the  sensation.  The  intensity  rela- 
tion between  the  stimulus  and  sensation  may  be  modified  by 
the  condition  of  the  sense-organs.  If  they  are  fatigued,  or 
if  adaptation  has  taken  place,  a  given  intensity  of  the  stim- 
ulus will  not  occasion  the  same  intensity  of  sensation  as  it 
would  if  the  sense-organ  were  not  fatigued  or  if  adaptation 
had  not  taken  place.  A  rose  gives  a  more  intense  sensation 
of  odor  when  first  brought  into  the  room,  but  after  the  sense- 
organ  has  become  fatigued  the  sensation  intensity  is  reduced. 

The  minimal  and  the  maximal  intensities  of  sensation  /\  ' 
mark  two  limiting  points  in  the  intensity  series  of  any  given  <* 
sensation.  The  stimulus  must  reach  a  certain  intensity  be- 
fore any  sensation  is  aroused.  A  very  weak  stimulus  fails 
to  produce  a  sensation.  The  point  at  which  the  stimulus 
becomes  strong  enough  to  arouse  sensation  is  called  the 
threshold  of  sensation,  or  lower  limit  of  sensation.1  The  point 
at  which  increase  in  the  intensity  of  the  stimulus  fails  to 
give  further  increase  in  the  intensity  of  the  sensation  is  called 
the  upper  limit  of  sensation.  It  should  be  noted  in  connection 
with  the  upper  limit  of  sensation  that,  when  stimuli  become 
increasingly  intense,  other  end-organs  than  those  of  the 
original  sensation  are  affected.  For  example,  a  very  loud 
sound,  bright  light,  or  intense  pressure-stimulus  will  affect 
the  pain-nerves.  The  presence  of  the  resulting  pain-sensa- 
tion is  not,  however,  to  be  taken  as  an  increase  in  the  inten- 
sity of  the  original  sensation. 

There  is  no  way  of  measuring  directly  the  intensity  of  a 
sensation.     We  can,  however,  compare  like  sensations  and  *  * 

1  It  is  necessary  for  the  stimulus  to  act  for  a  certain  length  of  time;  a  very    ^\x*X"'*> 
brief  stimulus  may  fail  to  arouse  sensation,  even  though  it  may  have  an  inten-     ^ 
sity  far  above  the  threshold. 


100 


PSYCHOLOGY 


say,  for  instance,  which  of  the  two  is  the  more  intense.  In 
fact,  we  can  "arrange  a  number  of  such  sensations  in  a  series 
of  intensities  from  the  lowest  to  the  highest.  We  can  then 
measure  the  different  intensities  of  the  stimuli  which  occa- 
sion the  sensations,  and  so  have  an  indirect  measure  of  the 
intensity  of  the  sensation.  We  may  start  with  a  given  stim- 
lus,  note  the  intensity  of  the  sensation  which  arises  from  it, 
and  then  increase  the  stimulus  until  we  are  able  to  detect  a 
"just-noticeable  difference"  in  the  intensity  of  the  sensation. 
Continuing  the  process  we  obtain  a  series  of  sensations  which 
are  just-noticeably  different  in  intensities,  each  sensation  pos- 
sessing a  just-noticeably  higher  intensity  than  the  one  before 
it.  Two  interesting  facts  reveal  themselves  in  such  experi- 
mental procedure.  If,  for  instance,  we  compare,  by  lifting 
successively,  weights  ranging  from  100  grams  to  105  grams, 
each  differing  from  the  other  by  one  gram,  we  find  that  we 
are  unable  to  sense  the  difference  between  the  weight  of  100 
grams  and  those  of  101,  102,  103,  and  104  grams,  respec- 
tively. Not  until  we  reach  105  grams  can  we  note  an  in- 
crease in  the  sensation,  i.  e.,  increasing  the  stimulus  does  not 
bring  an  increase  in  the  sensation  until  a  certain  increment 
to  the  original  stimulus  has  been  readied.  This  difference 
in  the  intensities  of  stimuli  required  to  cause  a  just-notice- 
able difference  in  the  sensation  is  called  the  difference-threshold. 
The  most  probable  explanation  of  this  fact  will  be  found 
in  the  nature  of  the  physiological  processes  in  the  sensory 
end-organs  and  nerves.  The  nervous  mechanism, is  such  that 
ascertain  inertia  of  the  end-organs  must  be  overcome  before 
an  added  increment  to  the  nervous  process  can  be  set  up. 
This  resistance  of  the  sense-organs  to  stimuli  also  explains 
the  existence  of  the  threshold,  or  lower  limit,  of  sensation.  A 
rough  analogy  may  be  seen  in  physical  inertia.  It  requires 
more  energy  to  start  a  piece  of  machinery  than  it  does  to 
keep  it  going  after  it  is  started,  and  more  to  change  its  rate 
of  movement  than  to  maintain  the  changed  rate  afterward. 
The  difference-threshold  expresses  the  increment  or  decre- 


SENSATION  10 1 

ment  \vhich  must  be  made  to  any  stimulus  before  any  differ- 
ence in  the  sensation  can  be  noticed. 

The  second  fact  is  that  equal  increments  to  the  stimuli 
do  not  produce  a  change  of  sensation  at  different  parts  of 
the  scale  of  intensities.  For  example,  it  requires  an  increase 
of  5  grams  to  a  loo-gram  weight  to  produce  a  just-noticeable 
difference  in  the  sensation.  But  if  5  grams  are  added  to 
200  grams,  no  difference  in  the  resulting  sensation  can  be 
detected.  It  requires  an  increase  of  10  grams  in  this  part 
of  the  intensity  scale  to  cause  a  noticeable  change  in  the 
sensation,  i.  e.,  the  difference- threshold  varies  for  different 
parts  of  the  scale.  In  general  we  may  say  that  absolute  dif- 
ferences in  stimuli  are  more  easily  detected  when  the  inten- 
sities of  the  stimuli  are  weak  than  when  they  are  strong. 
One  ounce  added  to  two  ounces  makes  a  noticeable  differ- 
ence, but  cannot  be  detected  when  added  to  ten  pounds.  A 
lighted  candle  brought  into  a  dark  room  (low  light-intensity) 
increases  the  illumination  of  the  room  very  noticeably,  but 
added  to  the  high  illumination  of  a  brightly  lighted  room 
causes  no  noticeable  difference  in  the  illumination. 

Weber's  Law  is  an  attempt  to  generalize  these  facts  and 
state  the  relation  of  the  intensity  of  the  stimulus  to  the  inten- 
sity of  sensation  more  exactly.  Briefly,  it  is  as  follows:  In 
order  to  obtain  an  increase  in  the  intensity  of  sensation,  the! 
original  stimulus  must  be  increased  by  a  constant  fraction  of 
itself.1  If,  as  has  been  stated,  an  increase  of  5  grams  to  the 
stimulus  of  100  grams  is  required  to  produce  a  just-noticeable 
increase  in  the  sensation,  and  an  increase  of  10  grams  for  the 
stimulus  of  200  grams,  then  the  constant  fraction  is  one- 
twentieth.  In  order,  then,  to  increase  the  sensation  of  any] 
weight-stimulus,  the  weight  must  be  increased  by  one-twen-\ 
tieth  of  itself.  The  fraction  which  gives  the  just-noticeable 
difference  of  sensation  is  not  the  same  for  all  senses.  For 
simultaneous  light  it  is  one  one-hundredth;  for  sound  one- 

1  Fechner's  modification  of  Weber's  Law  is  as  follows:  Intensity  of  sensa- 
tion increases  as  the  logarithm  of  the  stimulus. 

/\  UBRAIY 

UNIVERSITY  OF  CALIFORNIA 
SANTA  BARBARA 


102  PSYCHOLOGY 

fourth.  These  fractions  can  be  obtained  only  by  long  and 
careful  experimentation,  and  different  investigators  have  ob- 
tained different  values  for  the  constant  fractions.  It  has 
been  found  that  they  vary  for  different  persons  and  for  dif- 
ferent parts  of  the  intensity  scale  in  the  same  sense.  For 
very  high  and  very  low  intensities  Weber's  Law  does  not  hold 
at  all.  It  .applies  only  to  the  middle  range  of  intensity  values 
and  even  there  only  approximately.1  It  has  not  as  yet  been 
applied  to  sensations  of  temperature  and  taste.  The  most 
that  can  be  said  for  Weber's  Law  is  that  it  states  a  general 
fact  of  experience — the  fact  that  sensation  does  not  increase 
in  the  same  ratio  as  the  stimulus  and,  further,  that  in  order 
*  to  get  an  increase  in  the  sensation-intensity,  the  increment 
)  to  the  stimulus  must  constantly  be  made  greater  and  greater 
as  we  pass  from  the  lower  to  the  higher  intensities.  Or,  to 
restate  the  same  fact  in  another  way,  it  requires  a  greater 
and  greater  difference  in  the  intensities  of  two  stimuli  to 
produce  a  just-noticeable  difference  in  the  intensity  of  sensa- 
tions, as  we  go  from  the  lower  to  the  higher  intensities.  The 
strict  application  of  Weber's  Law  involves  the  assumption 
that  all  just-noticeable  differences  in  the  same  class  of  sensa- 
tions are  equal,  that  the  just-noticeable  difference  in  the 
sensations  produced  by  the  stimulus  of  100  grams  and  105 
grams  is  equal  to  the  just-noticeable  difference  between  the 
sensations  produced  by  200  grams  and  210  grams.  It  would 
further  assume  that  these  differences  are  units  of  sensation, 
and  that  the  total  sensation  in  each  case  is  made  up  of  these 
units  which  may  be  added  to,  or  subtracted  from,  the  sensa- 
tions. These  assumptions  have  never  been  proved.  There 
seems  to  be  no  reason  for  believing  that  a  just-noticeable  dif- 
ference in  sensations  of  low  intensity  is  equal  to  a  just- 
noticeable  difference  between  sensations  of  high  intensities. 
Nor  can  we  observe,  by  the  most  careful  introspection,  any 

1  For  a  summary  of  the  results  of  experimental  investigations  into  the  valid- 
ity of  Weber's  Law,  see  Ladd  and  Woodworth:  "  Physiological  Psychology," 
PP-  3fo"31§i 
' 


SENSATION  103 

evidence  for  the  assumed  fact  that  sensations  are  made  up 
of  intensity  units,  nor  can  we  measure  a  sensation  in  such  a 
way  as  to  be  able  to  say  how  many  units  of  intensity  it  con- 
tains. Every  sensation  is  itself,  so  far  as  we  are  able  to 
say  at  the  present  time,  a  unit  not  capable  of  being  broken 
up  into  smaller  units. 

Why  it  is  necessary,  in  order  to  get  a  just-noticeable  dif- 
ference in  sensation,  to  make  increasingly  larger  additions  to 
the  stimulus  as  its  intensity  increases,  raises  a  very  interest- 
ing theoretical  question.  Is  it  due  wholly  to  the  nature  of 
physiological  processes  in  the  end-organs  and  brain  centres? 
Or  is  it  due  to  purely  psychological  factors,  such  as  the 
theory  of  the  relativity  of  consciousness,  which  holds  that 
the  nature  or  value  of  every  conscious  state  is  determined  by 
its  relation  to  other  conscious  states?  According  to  the 
principle  of  relativity,  the  intensity  of  a  given  sensation 
resulting  from  an  increase  in  stimulus  depends  upon  the  in- 
tensity of  sensations  already  going  on,  or  sensations  just  pre- 
ceding. We  cannot  go  into  these  questions  at  this  time 
further  than  to  call  attention  to  these  possible  interpreta- 
tions of  the  facts  summarized  by  Weber's  Law.1 

Extensity. — Extensity  is  to  be  distinguished  from  extension. 
Extension  is  experienced  only  as  the  result  of  combining  sim- 
pler experiences  (distance,  direction,  and  position)  into  a 
mental  complex.  Extensity  is  an  original  and  native  aspect 
of  sensation — a  kind  of  "bigness"  within  which  there  are  no 
parts  or  diyisi.Qjqs  which  can  be  distinguished  from  other 
parts.  If  first  the  head  and  then  the  point  of  a  pin  are 
pressed  very  lightly  upon  the  forefinger,  so  that  the  point  of 
the  pin  does  not  stimulate  the  pain-nerves,  the  two  pressure- 
sensations  will  seem  different.  The  difference  is  that  of  ex- 
tensity.  The  sensations  are  without  any  space  form,  for 
there  is  no  distinguishing  of  parts,  yet  they  possess  different 

1  For  a  statement  of  these  theories  or  interpretations  of  Weber's  Law,  see 
Ziehen:  "Physiological  Psychology,"  pp.  54-61;  Ladd  and  Woodworth: 
"  Physiological  Psychology,"  pp.  374-9. 


104  PSYCHOLOGY 

degrees  of  native  "bigness"  or  extensity.  It  is  difficult  to 
isolate  this  attribute  of  sensation,  because  it  is  so  overlaid 
with  the  higher  and  more  complex  experiences  of  space  per- 
ception. Ex  tensity  _  shows  itself  to  introspection  rather  as 
the  bigness  of  the  sensation  than  as  the  size  of  objects^or 
spaces  suggested  by  the  sensations.  It  attaches  itself  more 
closely  to  the  intrinsic  nature  of  the  sensation  than  do  expe- 
riences of  extension.  The  visual  sensations,  the  cutaneous 
sensations,  the  articular,  and  muscular  sensations,  all  plainly 
have  the  extensity  attribute.  On  the  other  hand,  sounds, 
tastes,  and  smells  have  been  denied  extensity  by  some  psy- 
chologists, although  some,  chief  among  them  James,  believe 
that  all  sensations  possess  extensity.  The  roar  of  a  lion  is 
bigger  than  the  squeaking  of  a  mouse;  the  low  bass  note 
sounds  bigger  than  the  high  treble  note.1  Some  smells,  like 
the  heavy  odor  of  musk,  seem  more  voluminous  than  the 
lighter  ones,  such  as  the  odor  of  camphor;  the  taste  of  sweet 
is  more  voluminous  than  the  taste  of  sour.  Some  pains  are 
bigger  than  others.  The  fine,  shooting  pain  of  neuralgia  is 
less  voluminous  than  the  heavy  soreness  of  a  boil,  says 
James.2  '  The  extensity  differences  in  the  sensations  of  hear- 
ing, taste,  and  smell  are  evidently  not  so  great  as  they  are  in 
the  sensations  of  the  skin,  the  muscles,  and  the  eyes.  This 
more  limited  range  of  experienced  difference  in  the  former 
group  of  sensations  may  explain  the  obscure  part  that  ex- 
tensity  plays  in  them. 

The  physiological  basis  for  the  differences  of  extensity  in 
sensations  lies  in  the  differences  in  the  number  and  outspread 
of  nerve-ending,  Thegreater  the  number  of  nerve-endings 
stimulated,  the  greater  the  degree  of  extensity  in  the  result- 
ing sensation.  In  the  skin  and  on  the  retina  of  the  eye  we 
have  extended  nerve-elements,  which  are  capable  of  being 
stimulated  in  different  numbers.  The  stimulation  of  these 

1  For  James's  discussion,  see  his  "  Principles  of  Psychology,"  Vol.  II,  p.  134; 
"  Briefer  Course,"  p.  335. 
a  "  Briefer  Course." 


SENSATION  105 

nerve-elements  gives  an  attribute  of  spread-outness  which 
varies  with  the  size  of  the  area  and  number  of  nerve-elements 
stimulated  at  any  one  time.  The  nerve-endings  in  the  ear 
are  not  spread  out,  while  those  of  the  tongue  and  nose  are 
normally  stimulated  in  such  a  way  as  to  give  little  opportu- 
nity for  the  experience  of  extensity  differences. 

Duration. — Every  sensation  begins,  rises  to  its  fulness, 
and  then  wanes.  These  phases  are  really  not  differentiated 
from  each  other  in  ordinary  experience,  yet  they  furnish  the 
basis  for  a  simple  experience  of  duration  which  is  present  in 
all  sensation.  This  sensory  attribute  must  be  distinguished 
from  the  duration-of-time  perception,  which,  like  extension- 
in-space  perception,  is  the  result  of  the  synthesis  of  different 
sensations.  Duration  as  an  attribute  of  sensation  is  part 
and  parcel  of  the  sensation  itself.  It  must  not  be  confused 
with  the  perception  of  how  long  the  sensation  lasts.  It  is  the 
sensation  content  of  temporal  outspread  or  temporal  bigness, 
a  native  time  quantum.  Even  the  shortest  sensation  pos- 
sesses this  native  duration  attribute. 

Other  Attributes. — Besides  the  four  attributes  just  dis- 
cussed, other  attributes  have  been  suggested  as  essential 
characters  of  sensation.  Titchener1  mentions  clearness  as 
an  attribute.  Sensations  may  appear  in  the  foreground  or 
in  the  background  of  consciousness,  in  the  focus  or  in  the 
margin.  Now,  since  a  sensation  must  appear  somewhere 
between  these  limits,  it  always  possesses  some  degree  of 
clearness.  Miinsterberg2  gives  the  name  "vividness"  to  this 
attribute,  and  cautions  his  readers  against  confusing  vivid- 
ness of  sensation  with  intensity.  He  says:  "If  the  ticking  of 
a  clock  in  my  room  becomes  less  and -less  vivid  for  me  the 
more  I  become  absorbed  in  my  work,  till  it  finally  disappears, 
it  cannot  be  compared  with  the  experience  which  results 
when  the  clock  to  which  I  give  my  full  attention  is  carried 
farther  and  farther  away."  A  sensation  of  low  intensity 

1  "Text-Book  of  Psychology,"  p.  53. 

2  "Psychology  and  Life,"  p.  86. 


r 


106  PSYCHOLOGY 

may  have  a  high  degree  of  clearness  or  vividness,  while  a 
sensation  of  high  intensity  may  have  a  low  degree  of  clear- 
ness or  vividness.  The  changes  in  clearness  or  vividness 
seem  Jg  be  due  not  to  sensation  alone,  but  to  change^n 
attention! 

There  is  sufficient  evidence  to  believe  that  every  cutane- 
ous and  visual  sensation  possesses  a  particular  local  signifi- 
cance, which  is  different  for  every  part  of  the  skin  and  retina 
stimulated.  Close  your  eyes  and  have  some  one  touch  you 
with  the  point  of  a  pencil,  first  on  the  right  and  then  on  the 
left  hand.  You  are  able  to  tell  without  hesitation  which 
hand  is  touched.  This  means  that  each  sensation,  although 
alike  in  all  other  attributes,  differs  for  different  regions  of  the 
skin  stimulated.  This  difference  in  sensation  is  a  difference 

local  sign.  If,  however,  two  points  of  the  skin  which  lie 
>very  close  together  are  stimulated,  the  difference  of  local 
sign  disappears.  When  the  two  near  points  are  stimulated 
simultaneously,  the  two  stimuli  are  felt  as  one.  When  the 
distance  is  sufficiently  great,  however,  the  stimuli  are  dis- 
criminated and  felt  as  two.  This  is  because  the  difference 
in  their  local  signs  is  great  enough  to  distinguish  one  from 
the  other.  The  minimal  distance  of  separation  of  two  stimuli 
which  are  sensed  as  two  is  termed  the  "two-point  threshold." 

This  threshold  varies  for  different  parts  of  the  skin.  It  is 
smallest  for  the  tip  of  the  tongue,  lips,  and  fingers,  and  great- 
est for  the  regions  along  the  spine.  The  local-sign  difference 
cf  sensation  is  not  a  difference  of  space  perception,  in  which 
points  are  located  with  reference  to  each  other,  and  given 
definitely  perceived  distances  and  directions  between  them. 
It  is  simply  a  felt  difference  in  sensations  coming  from  differ- 
ent points  of  the  skin  surface.  It  is  possible  to  find  regions 
within  which  the  two  points  of  a  compass  are  felt  as  differ- 
ent, and  yet  no  perception  of  the  distance  or  direction  of  the 
points  from  each  other  is  present.  In  such  cases  there  is 
merely  a  local-sign  difference  in  the  sensations.  The  nearer 
the  points  are  together  the  more  the  sensations  are  alike; 


SENSATION  107 

the  farther  the  points  are  apart  the  more  definite  the  differ- 
ence in  the  local  sign. 

Visual  sensations  also  possess  local  significance.  Sensa- 
tions which  are  alike  in  every  respect  (in  quality,  intensity, 
etc.),  but  which  come  from  different  points  of  the  retina,  are 
sufficiently  unlike  to  enable  us  to  distinguish  the  stimuli 
which  occasion  them.  Here,  as  in  the  skin,  every  point  of 
each  retina  gives  a  sensory  character  different  from  the  char- 
acter of  every  other  point.1 

fr 

KINDS  OF  SENSATIONS 

Psychological  analysis  has  shown  that  the  old  common- 
sense  classification  of  the  sensations  into  the  five  senses  of 
seeing,  hearing,  tasting,  smelling,  and  feeling  (touch)  is 
inadequate.  There  are  many  more  than  five  senses.  The 
sense  of  "touch,"  for  instance,  has  been  resolved  into  the 
four  distinct  senses  of  pressure,  pain,  cold,  'and  Wjjrm£h. 
Each  one  of  these  has  its  own  particular  kino!  of  nerve-end- 
ings which  give,  when  stimulated,  a  unique  sensory  experi- 
ence, different  from  all  others. 

Obviously  we  shall  get  different  divisions  of  the  sensa- 
tions if  we  classify  them  according  to  the  stimuli  which  occa- 
sion them,  or  according  to  the  sense-organs  to  which  they 
correspond,  or  according  to  the  intrinsic  quality  of  the  sen- 
sations themselves.  A  thoroughgoing  classification  of  the 
sensations  based  upon  the  different  kinds  of  stimuli  which 
occasion  them  is  impossible,  because,  in  many  cases, 
not  know  the  exact  nature  of  the  stimulus  which  acts  upon 
the  sense^gan!  Such~is^the  case  in  the  sense  of  smell. 
Without,  however,  going  into  the  exact  character  of  the 
stimuli,  we  may  divide  the  sensations  into  three  classes, 

1  Every  point  in  one  retina  has  a  corresponding  point  in  the  other.  Sensa- 
tions from  these  points  have  the  same  local  significance.  This  is  demonstrated 
in  cases  where  two  stimuli  exactly  alike,  but  occupying  different  positions  in 
space,  are  not  distinguished  from  each  other.  This  is  illustrated  in  stereo- 
scopic vision,  where  two  pictures  occupying  different  positions  in  space  are 
seen  as  a  single  picture. 


108  PSYCHOLOGY 

according  as  their  stimuli  are  found  (i)  in  the  vital  organs 
of  the  body,  (2)  in  the  bodily  organs  of  locomotion,  or  (3)  in 
objects  external  to  the  body. 

i.  Organic  Sensations  (reporting  conditions  of  the  internal 
I  bodily  organs) . 

*\        2.  Kinaesthetic  Sensations   (reporting  movements  of  the 
yDody).1 

3.  Special  Sensations  (reporting  the  character  of  external 
objects) . 

If  we  classify  the  sensations  according  to  their  different 
sense-organs,  and  at  the  same  time  subdivide  them  into 
groups  according  to  their  intrinsic  qualities,  we  have  the  fol- 
lowing classification: 

1.  Organic  Sensations: 

(a)  Sensations  from  the  alimentary  canal. 

(b)  Sensations  from  the  respiratory  organs. 

(c)  Sensations  from  the  circulatory  system. 

(d)  Sensations  from  the  sex-organs. 

2.  Kinaesthetic  Sensations: 

(a)  Muscular,  sensations  from  moving  muscles. 

(b)  Tendinous,  sensations  of  pull  and  strain  in  tendons. 

(c)  Articular,   sensations   of  gliding   and  pressure   in 

joints. 

(d)  Sensations  from  vestibule  and  semicircular  canals: 

sensations  of  position,  change  of  movement  and 
dizziness. 

3.  Cutaneous  Sensations: 
(a)  Pressure. 

(d)  Pain. 

(c)  Cold. 

(d)  Warmth. 

1  The  kinaesthetic  sensations  are  sometimes  classified  under  the  organic 
sensations.  For  instance,  Titchener,  in  Baldwin's  "  Dictionary  of  Philosophy 
and  Psychology,"  classifies  the  organic  sensations  into:  (i)  Muscular  sensa- 
tions, (2)  alimentary  sensations,  (3)  sexual  sensations,  (4)  static  sensations,  (5) 
respiratory  sensations,  and  (6)  circulatory  sensations.  The  muscular  and  static 
sensations  of  Titchener's  classification  are  in  this  text-book  placed  under  the 
kinaesthetic  sensations. 


SENSATION  X*  ICQ 

4.  Olfactory  Sensations:  s    * 

(Many  sensations,  but  no  characteristic  groups  of  qual- 
ities have  been  made  out.) 

5.  Gustatory  Sensations' 
(a)  Sweet. 

(6)  Sour. 

(c)  Salt. 

(d)  Bitter. 

6.  Auditory  Sensations: 
(a)  Noises. 

(6)  Tones. 

7.  Visual  Sensations: 

(a)  Achromatic  (brightness). 

White. 

Gray. 

Black. 
(6)   Chromatic  (color). 

Red. 

Yellow. 

Green. 

Blue. 

The  classification  here  given  is  not  at  all  satisfactory 
from  the  psychological  point  of  view,  but  it  is  the  best  that 
can  be  made  at  the  present  time.  In  the  first  place,  some 
of  the  subheadings  signify  elementary  sensory  experiences 
which  cannot  be  further  analyzed,  as  for  instance  those  of 
pressure,  pain,  warmth,  and  cold;  while  others,  like  those 
under  Organic  and  Kinaesthetic  Sensations,  signify  highly 
complex  experiences,  i.  e.,  are  made  up  of  simpler  sensations. 
The  so-called  sensations  of  hunger,  thirst,  and  nausea  from 
the  alimentary  canal,  the  sensations  from  the  sex-organs,  the 
muscular,  tendinous,  and  articular  sensations  may  not  present 
any  distinct  sensory  qualities  at  all,  but  may  be  nothing 
more  than  certain  combinations  and  blends  of  pressure,  pain, 
and  temperature  sensations.  Or,  at  least,  they  may  be  prim- 
itive and  undifferentiated  forms  of  these  sensations. 


CHAPTER  V 

ORGANIC,  KIN^STHETIC,  AND  CUTANEOUS 
SENSATIONS 

ORGANIC  SENSATIONS 

The  organic  sensations  include  a  great  mass  of  undiffer- 
entiated  and  vague  sensory  experiences  that  are  located  in 
and  about  the  vital  organs.  From  the  visceral  or  abdominal 
region  come  dull  internal  pains  of  varying  intensities,  vague 
sensations  of  fulness,  tension,  and  pressure.  From  the  upper 
part  of  the  alimentary  canal  we  get  the  more  definite  experi- 
ences of  hunger,  thirst,  and  nausea.  Hunger,  is  located  in 
the  stomach  as  a  dull,  gnawing  pain  or  ache.  Thirst  is  felt 
quite  definitely  in  the  back  part  of  the  mouth,  and  in  the 
throat  as  an  insistent  pressure  combined  with  a  sense  of 
roughness  and  dryness.  Nausea  is  felt  in  the  oesophagus 
and  stomach,  and  is  difficult  to  analyze  into  its  constituent 
elements  of  sensation.  In  the  thpracjc  region  we  sometimes 
experience  a  sense  of  a  want  of  ajr?  stuffiness,  or,  even  more 
intensely,  suffocation,  due  to  the  physiological  condition  of 
the  lungs  when  shut  off  from  an  adequate  air-supply.  The 
sensations  coming  from  the  acts  of  respiration  arise  from  the 
intercostal  muscles  and  diaphragm,  and  should  be  classed 
among  the  kinaesthetic  sensations.  While,  ordinarily,  we  do 
not  sense  the  condition  of  the  heart,  yet  in  fright,  anger,  and 
other  emotions,  and  also  during  and  after  extreme  physical 
xertion,  sensations  *r'v^  in  f^p  rar^i^r  rppirm  In  fright 
there  is  a  smkingsensatipn,  caused  probably  by  the  sudden 
change  m"The^eart7s  action.  In  anger  and  heavy  physical 
exertion  there  appears  a  vague,  rhythmic  tension  about  the 
heart.  The  "heart  jumping  up  in  the  mouth"  probably 

no 


ORGANIC   SENSATIONS  III 

comes  from  the  sensations  of  muscular  contraction  in  the 
pharynx.  The  sex-organs  add  another  group  of  sensations 
to  the  organic  experiences.  The  organic  experiences,  so  far 
mentioned,  are  without  doubt  highly  complex  products,  com- 
pounded out  of  simpler  sensations.  If  analysis  were  not  so.  .*> 


.  . 

difficult  here,  we  should  probably  be  able  to  resolve  these  I 
experiences  into  sensations  very  much  akin  to  those  of  pres- 1 
sure,  pain,  cold,  and  warmth  of  the  cutaneous  sensations. 
The  stimuli  which  set  up  these  organic  experiences  consisti 


in  the  physiological  condition  of  the  organs  themselves,  which  1] 
affects  the  sensory  nerve-endings,  and  thus  gives  rise  to  the* 
experience.     In  cases  where  vital  organs  are  not  supplied 
with  sensory  nerves,  any  serious  disturbance  in  such  organs 
is  experienced  as  pain  in  neighboring  sensitive  tissue. 

It  is  interesting  to  note  that  some  of  the  ancient  writers 
located  the  feelings  and  emotions  in  the  vital  organs,  and 
modern  investigators  have  pointed  out  more  definitely  the 
close  connection  between  the  vague  and  unanalyzable  organic 
sensations  on  the  one  hand  and  the  feelings  and  emotions  on 
the  other.  The  condition  nf  thfi  vitnl  processm  hns  mnrh  j 
to  do  in^deteimmmgjbhejiaturp  oj  Jkg.  qpotional  Jnne.  I 
digestion  will  predispose  one  to  a  pessimistic  and  gloomy 
point  of  view,  while  a  healthy  digestion  tends  to  cheerful-  \  efa*+A 
ness.  Ordinary  speech  has  several  expressions  which  recog- 
nize the  idea  that  the  emotions  are  based  upon  organic  con- 
ditions and  disturbances:  "The  bowels  of  compassion,"  "the 
complacency  of  a  full  stomach,"  "the  bile  of  one's  wrath," 
"the  emotions  of  the  heart,"  "his  heart  is  in  his  work,"  etc. 
Even  among  psychologists  the  theory  has  been  entertained 
that  the  feelings  are  unclear  and  undifferentiated  organic 
sensations1 — diffuse  organic  experiences  that  arise  from  the 
stimulation  of  unspecialized  nerve-endings,  and  therefore  do 
not  stand  out  clearly  in  consciousness  with  definite  sensory 
qualities  as  do  the  other  groups  of  sensations.  It  is  certainly 
true  that  many  of  the  organic  sensations  are  obscure,  very 

kitchener:  "A  Text-Book  of  Psychology,"  §  74.  - 


112  PSYCHOLOGY 

vaguely  located,  refer  to  the  organism  as  a  whole  rather  than 
to  any  definitely  distinguishable  part  of  it,  and  consequently 
appear  as  subjective  modifications  or  attitudes.  On  the 
other  hand,  the  special  sensations  refer  to  the  characteristics 
of  objects  that  appear  to  exist  independently  of  our  conscious- 
ness. Many  of  the  organic  sensations  are  altogether  unpro- 
jected,  ^eTphave  no  reference  beyond  themselves,  sugggst 
nothing  over  and  above  the  subjective  experience 


*        All  these  characteristics  make  the  more  obscure  organic  sen- 

sations strikingly  similar  to  our  feeling  or  affective  experi- 

.    ences.     However  this  may  be,  the  organic  sensations  furnish 

1    a  continuous  and  constant  accompaniment  or  background  of 

'    all  mental  experiences.     We  are  never  free  in  normal  waking 

01    life  from  this  undertone  of  inner  bodily  experiences. 

KlNJESTHETIC    SENSATIONS 

Muscle,  Tendon,   and  Joint   Sensations.  —  The   muscles, 

<  tendons,   and  articular  surfaces  are  supplied  with  sensory 

nerve-endings  which  give,   when   stimulated,   sensations   of 

movement.     These  sensations,  together  with  the  sensations 

'  *•*•    *  that  arise  from  the  vestibule  and  semicircular  canals  of  the 

inner  ear,  are  known  as  kinasthetic  sensations. 

The  sensory  end-organs  consist  of  muscle-spindles  and 
tendon-spindles  in  which  fine  branchings  of  nerve-filaments  lie 
next  to  or  coil  about  the  muscle  and  tendon  fibres  within 
the  spindles.  Other  nerve-endings  —  Pacinian  corpuscles  and 
end-bulbs  —  are  found  in  the  muscles,  tendons,  joints,  and 
\j  ^periosteum.  It  is  probable  that  they,  too,  have  to  do  with 
fj.  the  sensations  of  movement. 

The   stimuli   which   excite   these   nerve-endings   are   the 
contraction  and  relaxation  of  the  muscles,  the  pull  and  ten- 
sion of  the  tendons,  and  the  gliding  of  the  tendons  over  the 
/\  joints,  and  possibly  the  pressure  of  the  joint  surfaces  against 
i*      *•  Veach  other. 

The  muscle,  tendon,  and  joint  sensations  are  blended  with 
the  cutaneous  sensation  of  pressure  whenever  we  move  any 


L 

J  sio 


KESLESTHETIC    SENSATIONS 


part  of  the  body.  The  cutaneous  sense  is  stimulated  when 
the  body  changes  its  position  by  the  folding,  stretching,  or 
pulling  of  the  skin.  In  order  to  study  the  kinaesthetic  sensa- 


rfnc 


FIG.  38. — Tendon  with  nerve-plaque  made  up  of  the  endings  of  sensory  fibres 

seen  entering  from  above,     rfnc,  arborization  of  the  sensory  fibres. 

(From  Ladd  and  Woodworth,  after  Ciaccio.) 

tions  alone,  we  must  find  some  way  of  isolating  them  from 
the  skin  sensations.  This  may  be  done  by  making  the  cufca^ 
neous  tissue  anaesthetic  by  the  use  of  cocaine  or  ether  spray. 


FIG.  39. — Nerve-plaque  in  a  muscle-spindle.     The  nerve-fibre  entering  at  the 

left  subdivides  to  form  the  network  shown. 
(From  Thorndike's  "Elements  of  Psychology,"  after  Barker.) 

It  is  almost  impossible  to  separate  the  muscle,  tendon,  and 
joint  sensations  from  each  other,  for  the  reason  that  most 
movements  awaken  all  three  at  once.  But  those  who  have 


114  PSYCHOLOGY 

had  practice  in  introspection  may  be  able  at  times  to  pick 
out  these  different  sensory  experiences  from  each  other.  By 
gripping  the  hand  tightly,  one  gets  a  dull  internal  pressure- 
like  sensation  in  the  muscles  of  the  forearm.  Practically  the 
same  sensation  may  be  obtained  by  pressing  upon  the  mus- 
cles of  the  arm  with  the  hand.  The  sensation  will  stand  out 
more  clearly  if  the  skin  surface  has  been  previously  made 
anaesthetic. 

The  tendon  sensation  appears  when  one  lifts  a  heavy 
'Jlr        weight  by  pulling  directly  upward  with  the  arm  and  allowing 
the  weight  to  hang  perpendicularly  from  the  shoulder.     While 
the  sensation  in  question  is  qualitatively  different  from  the 
muscle  sensation  aroused  at  the  same  time,  we  are  unable 
to  describe  it  further  than  to  say  that  it  is  a  sensation  of 
pull  or  strain  in  the  wrist  and  elbow  joints. 
;       The  joint  or  arfrifiular  sensations  are  not  so  clearly  made 
«put  as  the  muscle  and  tendon  sensations.     But  if  the  left 
4  'j^r     forefinger  is  grasped  firmly  between  the  thumb  and  the  first 
v^^*    two  fingers  of  the  right  hand  and  pressed  inward  while  the 
finger  is  bent  back  and  forth  at  the  middle  joint,  a  smooth, 
gliding  sensation  will  be  experienced  which  seems  very  much 
like  a  light  internal  pressure.     One  must  disregard  the  cuta- 
neous pressure  caused  by  grasping  the  finger  by  the  other 
hand. 

As  a  proof  that  these  sensations  really  play  the  chief  part 
in  our  perceptions  of  movements  and  positions  of  the  limbs, 
we  may  point  out  the  fact  that  complete  anaesthesia  of  the 
skin  surface  does  not  interfere  materially  with  the  ability  to 
perceive  the  position  and  movement  of  any  member  of  the 
body,  while  anaesthesia  of  the  joints  or  of  the  muscles  and 
tendons  seriously  interferes  with  such  perception  and  reduces 
the  power  of  making  co-ordinated  movements. 

We  shall  see  later,  when  we  take  up  the  combination  of 
sensations  into  space  perceptions,  that  a  large  part  of  the 
raw  material  out  of  which  these  perception  complexes  are 
formed  is  drawn  from  the  kinsesthetic  sensations.  We  de- 


s  I 
el 
s! 


KIN^STHETIC    SENSATIONS  1  15 

pend  very  largely  upon  these  sensations  for  the  conscious 
material  out  of  which  we  construct  our  space  world.     Not 
only  the  sensations  which  arise  in  the  larger  muscles  and 
their  adjacent  joints  and  tendons,  but  the  finer  muscles  con-  • 
*  trolling  convergence,  divergence,  and  accommodation  in  the  ' 
)  eyes  furnish  conscious  elements  which  are  combined  with  the* 
1  tactual  and  visual  sensations  into  definite  space  perceptions.  1 
It  is  important  that  the  student  should  bear  in  mind 
from  the  beginning  that  these  sensations  —  in  fact,  all  sensa- 
tions  —  are  only  the  psychological  elements  out  oL  which  the_ 
complexes  of  perception  and  other^  higher  mental  processes 
are_built  up.     These  sensations  must  be  thought  of  only  as 
simple   qualities  of  consciousness,   and  never  as   the  mor 
highly  developed  perceptions  of  weight,  definite  perceptions 
of  position,  direction,  or  distance.     These  latter  experiences 
are  complexes  of  sensations  which  we  gain  through  experi- 
ence by  associating  and  combining  the  elementary  sensations 
in  various  ways.1 

Sensations  from  Vestibule  and  Semicircular  Canals.  —  A 
set  of  rather  obscure  and  unobtrusive  sensations  arises  in 
the  vestibule  and  semicircular  canals  of  the  ear.  With  slight 
stimulation  of  these  organs,  it  requires  very  careful  introspec- 
tion to  detect  their  presence  in  consciousness.  They  appear 
as  swimming  sensations  in  the  head,  dizziness,  sensations 
coming  from  the  position  and  sudden  change  of  the  move- 
ment  of  the  head,  or  the  body  as  a  whole.  They  jplay^  an 
important  part  in  maintaining  the  positioning^  equilibrium 
of  the  body.  The  movements  which  restore  disturbed  equi- 
librium are  known  as  "compensatory  movements."  They 
are  present  in  nearly  all  animals.  If,  for  instance,  the  body 
is  forced  from  its  upright  position,  when  such  a  position  is 
advantageous  or  desired,  immediately  the  compensatory  re- 
flexes throw  the  head  and  body  back  to  their  normal  posi- 
tions. In  cases  of  extirpation  of  the  vestibule  and  semi- 
circular canals  in  animals  the  sense  of  equilibrium  is  lacking, 

1  See  Titchener:  "  A  Text-Book  of  Psychology,"  §48  and  §50. 


Il6  PSYCHOLOGY 

as  is  shown  by  the  loss  of  compensatory  movements,  dis- 
turbed locomotion,  running  in  a  circle,  unusual  positions  of 
the  head,  etc.  Deaf-mutes,  whose  internal  ear,  including  the 
vestibule  and  canals,  is  destroyed,  do  not  experience  the  sen- 
sations of  swimming  in  the  head,  or  dizziness  when  rotated 
in  a  revolving  chair,  or  when  whirling  on  the  heel.1  These 
facts  point  to  the  vestibule  and  semicircular  canals  as  con- 
taining the  sense-organs  for  the  sensations  under  discussion. 
/The  vestibule  and  semicircular  canals  form  the  upper  part 

/  of  the  internal  ear,  the  lower  part  of  which  is  the  cochlea, 

\  the  true  sense-organ  of  hearing. 

/  On  the  inner  walls  of  the  membranous  semicircular 
canals,  and  within  the  utricle  and  saccule  of  the  vestibule, 
'are  tufts  of  hair-like  cells  projecting  into  the  endolymph,  a 
fluid  which  fills  the  canals.  The  hair-like  cells  in  the  utricle 
and  saccule  support  a  number  of  crystal-like  formations,  or 
otoliths,  which  are  held  in  place  by  a  gelatinous  substance. 
About  the  base  of  these  hair-cells  and  those  in  the  semi- 
circular canals  are  distributed  the  nerve-endings  of  the  ves- 
tibular  nerve,  whose  fibres  connect  with  the  cerebellum. 

The  stimulus  which  acts  upon  the  hair-cells  consists  in 
the  varying  pressure  of  the  endolymph,  which  bends  them 
whenever  any  change  of  position  or  movement  of  the  head 
takes  place.  The  canals  of  the  ear  lie  in  different  pknes,  one 
horizontal  and  two  vertical,  at  right  angles  to  each  other. 
The  position  of  the  canals  is  such  that  any  movement  of  the 
head  will  cause  the  endolymph  to  act  upon  the  hair-cells  in 
one  or  more  pairs  of  canals.  Head  movements  will  cause  a 
lag  or  back-flow  of  endolymph  in  the  canals,  thus  bending  the 
hair-cells  in  an  opposite  direction  to  the  movement  and  so 
exciting  the  nerve-fibres.  Therefore,  turning  rapidly  upon 
the  heel  will  cause  swimming  sensations  in  the  head  in  the 
direction  of  the  movement.  The  sensation  will  continue 


eaf-mutes  depend  upon  visual  sensations  for  sensory  cues  to  position 
quilibrium.     When  their  eyes  are  closed  or  blindfold 
ided  disturbance  of  the  sense  of  position  and  equilibrium. 


fl       .    anjT  equilibrium.     When  their  eyes  are  closed  or  blindfolded,  they  show  a 
1»>  ' 


KINLESTHETIC    SENSATIONS  117 

until  the  fluid  in  the  canals  affected  takes  up  the  motion  of 
the  head.  Then  they  will  cease.  If  movement  is  suddenly 
arrested,  and  we  stand  still  after  whirling  upon  the  heel,  we 
experience  the  swimming  sensations  in  the  direction  opposite 
to  the  original  movement,  because  when  we  stop  the  endo- 
lymph  continues,  for  a  time,  its  movement  forward,  and  so 
bends  the  hair-cells  in  the  direction  of  the  original  move- 
ments and  reverses  the  sensation.  The  direction  of  the 
swimming  sensation  may  be  changed  from  the  horizontal  to 
the  vertical  plane  by  inclining  the  head  on  the  shoulder  dur- 
ing rotation,  and  then  raising  it  to  an  upright  position  when 
the  rotation  is  stopped.  We  then  get  the  swimming  sensa- 
tions in  the  vertical  directions.  Under  these  conditions, 
when  the  head  is  bent  down  upon  the  shoulder  the  vertical 
canals  are  brought  more  nearly  into  the  plane  of  rotation, 
and  consequently  the  endolymph  in  these  canals  is  affected 
more  by  the  movement  of  rotation  than  in  the  others,  with 
the  result  that  the  sensations  correspond  in  direction  to  the 
plane  of  the  canals. 

With  a  little  practice  the  student  may  learn  to  observe 
the  swimming  sensations  during  and  just  after  sudden  move- 
ments of  the  head  in  any  direction.  The  more  intense  of 
these  sensations  are  commonly  known  as  sensations  of  diz- 
ziness, or  rotation. 

The  hair-cells  in  the  utricle  and  saccule  are  weighted  with 
otoliths,  which  make  them  still  more  sensitive  to  the  differ- 
ent positions  of  the  head.  These  otoliths  drag  down  upon 
the  hair-cells,  pulling  in  the  opposite  direction  to  any  change 
of  position.  By  exerting  varying  tensions  in  different  direc- 
tions, according  to  the  position  of  the  head  and  body,  vague 
pressure-sensations  are  set  up  which  serve  as  indices  of  posi- 
tion, equilibrium,  and  locomotion.1 

1  For  a  more  complete  treatment  of  the  sensations  of  the  vestibule  and 
semicircular  canals,  see  Ladd  and  Wood  worth:  "  Elements  of  Physiological 
Psychology,"  §34,  §35,  and  §36,  pp.  208-212.  Titchener:  "A  Text-Book  of 
Psychology,"  §§5i-S5>  PP-  173-182. 


Il8 


PSYCHOLOGY 


CUTANEOUS  SENSATIONS 

An  object  placed  against  the  skin  surface  arouses  a  num- 
ber of  sensations,  all  at  the  same  time :  sensations  of  pressure, 
warmth  and  cold,  and,  in  some  cases,  pain. 
Although  by  careful  observation  we  can 
readily  distinguish  the  different  qualities  of 
these  sensations  from  each  other,  we  usually 
think  of  the  combined  effect  of  all  these  sen- 
sations of  the  skin  as  the  "sense  of  touch." 


-Of 


FIG.  40.  —  Dia- 
gram showing 
the  nerve-end- 
ings in  skin. 
(Retzius.) 

(Taken  from  Quain's 
"Elements  of 
Anatomy.") 


and 


The  experiences  which  we  get  from  this  so- 
called  "sense  of  touch"  are  not  simple  ex- 
periences. Hard 
and  soft,  smooth 
and  rough,  wet  and 
dry,  sharp  and 
blunt,  round  and 
rubical,  are  the  re- 
sult not  of  a  single 
sense,  but  of  com- 
bining different  cu- 
taneous sensations. 
Even  the  muscular 
articular  sensations  may  be 
part  of  these  complex  experiences.1 
The  experiences  which  we  get 
from  the  skin  as  a  whole  need  to 
be  analyzed  into  their  elements, 
and  so,  in  the  following  sections, 
we  shall  treat  of  each  cutaneous 
sense  alone. 

The  End- Organs. — The  cutane- 
ous sense  areas  consist  of  the  skin,  lip  surfaces,  lining  mem- 
brane of  the    mouth    and   throat    cavity,   conjunctiva   and 


FIG.  41. — Corpuscle  of  Meiss- 
ner:  n,  sensory  fibre;  a, 
its  branching  termination 
within  the  corpuscle. 

(From  Ladd  and  Woodworth,  after 
Ranvier.) 


1See  Titchener:  "Text-Book  of  Psychology,"  p.  171,  §50,  and  Ladd  and 
.Woodworth:  "  Physiological  Psychology,"  p.  347,  §26. 


CUTANEOUS   SENSATIONS  IK) 

cornea  of  the  eye.  In  these  areas  and  in  the  tissue  imme- 
diately underneath  are  several  kinds  of  nerve-endings,  show- 
ing various  terminal  formations. 

About  the  roots  of  the  hairs  which  are  found  on  a  large 
part  of  the  skin  surface  are  coiled  the  terminal  branches  of 
sensory  nerves.  These  are  stimulated  by  touching  the  hairs, 
or  the  skin  on  the  "windward"  side  of  the  hairs.  In  the 
papillae  or  among  the  epithelial  cells  of  the  palms,  soles,  and 
lip  surfaces,  where  hairs  are  not  present,  are  a  large  num- 


FIG.  42.  —  Plume-organs  of  Ruffini  with  the  sensory  fibre's  arborization. 
(From  Thorndike's  "Elements  of  Psychology,"  after  Barker.) 

ber  of  tactile  nerve-endings,  called  "Meissner's  corpuscles." 
Each  corpuscle  consists  of  a  small,  oval  body,  about  which 
nerve-fibres  intertwine  and  then,  entering  the  interior  of  the 
corpuscle,  end  in  small  enlargements.     To  the  nerve-endings  *  i 
about  the  hair-roots  and  the  corpuscles  of  Meissner  is  as-  1\ 
cribed_thesense  of  pressure. 

The  simplest  form  of  end-organ  is  that  of  the  "free  nerve- 
endings,"   consisting   of   nerve-fibres  which  have  lost  their 
medullated  sheath  and  lie  between  the  epithelial  cells  of  the       ' 
epidermis.     They  have  been  found,  also,  in  the  cornea  of  /ifr 
the  eye,  where  the  sensation  of  pain  is  very  prominent.     The 
trip  end-organs  for  pain. 


In  the  deeper  layers  of  the  skin  are  found  cylindrically 
shaped  bodies  with  very  finely  divided  nerve-fibrils,  forming 
a  small  plume-like  structure.  They  are  known  as  the  "plume- 


1 2O 


PSYCHOLOGY 


y 

^r      organs  of  Ruffini"  and  to  them  is  attributed  the  sense  of 
>Jr  warmth. 

From  the -fact  that  the  "end-knob  of  Krause"  (consisting 
of  a  small  spherical  body  of  granular  matter,  into  which 
unmedullated  nerve-fibres  pass  and  end  in 
a  coiled  mass),  is  found  in  the  conjunctiva 
of  the  eye,  which  possesses   sensitivity  to      » 
cold,  but  not  tactile  sensation,  and  in  the    p 
mucous  membrane  of  the  mouth,  which 
is  especially  sensitive  to  cold,  it  is  argued 
that  the  "end-knob  of  Krause"  is  the  sen- 
sory end-organ  for  cold. 

The  "Pacinian  Corpuscles"  found  in 
the  subcutaneous  tissue  may  possibly 
serve  as  the  sense-organs  for  heavy  pres- 
sure, as  distinguished  from  the  lighter  pres- 
sure of  the  skin. 

The  suggested  correlation   of   the  dif- 
ferent   cutaneous    sensations    to    definite 
nerve-endings   cannot    be   taken  as  final. 
The   evidence    at   best   is    only    indirect. 
Even  where  the  evidence  seems   convinc- 
ing, there  are  some  perplexing  facts.     For 
instance,  the  "tactile  corpuscles"  are  very 
numerous  in  just  those  parts  of  the  skin  which  are  most  sen- 
sitive to  pressure,  and  very  few  or  practically  absent  from 
parts  of  the  skin  where  this  sense  is  dull.     This  seems  to  be 
good  evidence  for  assuming  that  the   "tactile  corpuscles" 
are  the  sense-organs  for  pressure.     But  it  has  been  proved 
that  some  parts  of  the  skin  that  possess  sensitivity  to  pres- 
sure are  lacking  in  this  particular  kind   of  end-organ.     Of 
course,  it  may  be  that  some  of  the  senses  have  more  than 
one  form  of  nerve-ending. 

The  Brain  Centres. — The  cortical  centres  for  the  cuta- 
neous sensations  are  in  the  region  along  the  fissure  of  Ro- 
lando, in  the  so-called  somaesthetic  area.  This  area  consti- 


Fig.  43. — End-knob 
of  Krause:  n, 
sensory  fibre;  t,  its 
branching  termi- 
nation within  c, 
the  capsule. 

(From  Ladd  and  Wood- 
worth,  after  Dogiel.) 


CUTANEOUS   SENSATIONS  121 

tutes  the  brain  centre  for  the  "muscle-sense,"  as  well  as  the 
centre  for  the  cutaneous  sense.  (See  Figure  28.)  The  exact 
boundary  of  the  somaesthetic  area  is  not  yet  made  out  clearly. 
Most  physiologists  place  it  in  the  region  just  posterior  to  the 
fissure  of  Rolando,  opposite  and  corresponding  to  the  motor 
centres  which  lie  on  the  anterior  side  of  the  fissure.  Within 
the  somaesthetic  area  the  skin  of  the  feet  and  legs  is  repre- 
sented by  the  upper  part  of  the  area,  the  skin  of  the  trunk 
and  arms  by  the  middle  part,  while  the  head  is  represented 
by  the  lowest  part.  So  that,  with  respect  to  the  cutaneous 
sensations,  a  man  may  be  said  to  stand  on  his  head  in  his 
brain.  A  lesion  in  this  region,  on  one  side  of  the  brain,  is 
attended  by  a  loss  of  all  the  cutaneous  sensations  (except 
pain)  on  the  opposite  side  of  the  body.  The  centre  for  pain 
has  not  been  located. 

Pressure-Sensations. — If  an  object  is  pressed  upon  the 
skin  surface  lightly,  the  resulting  sensation  of  pressure  is 
different  in  quality  from  the  sensation  aroused  by  a  more 
intense  pressure  contact.  The  latter  sensation  has  a  dull, 
heavy  quality,  akin  to  a  slight  ache.  It  appears  to  come 
from  the  underlying  muscles  and  is  probably  the  result  of 
excitation  of  sensory  nerves  among  the  muscle-bundles.  We 
shall,  accordingly,  distinguish  between  " light  pressure"  and 
' '  heavy  pressure.' ' 

It1  any  portion  of  the  skin  surface  (say  a  half-inch  square 
on  the  volar  side  of  the  forearm)  is  completely  explored  with 
the  end  of  a  soft  bristle  (a  horsehair  2  cm.  long)  that  will 
bend  easily  and  will,  therefore,  not  exert  too  strong  a  pres- 
sure, it  will  be  found  that  certain  parts  of  the  area  do  not 
respond  with  any  sensation  at  all.  But  certain  other  parts, 
"pressure  spots,"  will  respond  with  a  clear-cut  sensation  of 
pressure.  These  pressure  spots  appear  to  be  permanently 
located.  They  are  distributed  in  an  irregular  manner  and 
vary  very  much  for  different  parts  of  the  skin.  They  are 
most  plentiful  in  the  finger-tips,  where  the  corpuscles  of 
Meissner  are  found  in  large  numbers.  On  the  hairy  parts 


)l 


122  PSYCHOLOGY 

of  the  skin  a  pressure  spot  is  usually  found  on  the  windward 
side  of  each  hair,  just  over  the  hair-root,  or  follicle.  They 
are  also  found  on  the  surfaces  between  the  hairs.  They 
react  when  the  skin  is  pulled  or  stretched,  as  well  as  when 
pressure  is  applied.  This  punctiform  character  of  the  pres- 
sure surfaces  is  shared  by  all  the  other  cutaneous  senses. 
Within  the  same  area  we  shall  find  pain  spots,  cold  spots,  and 
warm  spots.  The  warm  spots  are  fewest  in  number,  while 
the  pain  spots  are  most,  mimerousithe  pressure  and  cold 
spots  are  equally  numerous  on  jnost  skin  areas. 

It  must  be  remembered  that  the  pressure  spots  can  be 
discovered  only  by  light  pressure.  If  the  pressure  upon  any 
point  of  the  skin  is  increased  the  skin  is  indented,  causing 
neighboring  sensitive  areas  to  react  so  that  any  point  of  the 
skin  is  sensitive  to  ordinary  pressures.  This  explains  why 
pressure  appears  to  be  continuous.  Pressure-sensation  arises 
not  only  from  pressure  applied  to  the  skin  surface,  but  from 
the  muscle-bundles  and  from  the  joint  surfaces,  when  they 
are  pressed  together.  This  we  may  call  ''heavy  pressure." 

The  acuity  or  delicacy  of  pressure-sensations,  as  measured 
by  the  lightest  pressure-stimulus  that  will  cause  a  just-notice- 
able sensation,  varies  for  the  different  parts  of  the  skin.  It 
is  most  acute  for  the  tips  of  nose,  tongue,  lips,  finger-tips,  and 
forehead,  and  bluntest  for  the  loins,  the  shins,  and  the  soles. 
It  requires  from  twelve  to  sixteen  times  more  pressure  to 
excite  a  minimal  sensation  on  the  latter  surfaces  than  it  does 
on  the  former. 

The  "two-point  threshold,"  or  just-noticeable  local  dif- 
ference, also  varies  for  the  different  parts  of  the  skin.  On 
the  tip  of  the  tongue  the  points  of  a  compass  may  be  sensed 
as  two  when  they  are  i  mm.  apart;  on  the  finger-tip,  2  mm.; 
on  the  outer  surface  of  the  lips,  5  mm.;  the  inner  surface, 
20  mm.;  on  the  back  of  the  hand,  30  mm.;  along  the  spine, 
54  mm. 

Pain-Sensation. — As  in  pressure,  so  in  pain  sensations,  we 
distinguish  between  the  cutaneous  pain-sensations  and 


CUTANEOUS   SENSATIONS 


123 


the  dull  subcutaneous  ache.  Pain  is  very  widely  distrib- 
uted, coming  from  nearly  all  parts  of  the  body.  There  are 
some  exceptions.  Certain  portions  of  the  visceral  and  other  JJ 
vital  organs  are  devoid  of  all  sensation.  A  small  area  on  the 
inner  side  of  each  cheek  is  insensitive  to  pain-stimuli.  On 
the  other  hand,  the  cornea  of  the  eye  seems  to  possess  only 
pain-sensations,  or  at  least  the  threshold  of  pain  is  so  low 
that  no  other  sensations  can  break  through  the  sensory  ex- 
perience of  pain  when  the  cornea  is  stimulated.  From  the 
fact  that  pain-sense  is  so  widely  distributed  in  practically 

all  parts   nf   the   boHyj    it   has   generally   hfP"    ™>nrgrr»grl    ^  a 

"common  sensation,"  with  no  specific  end-organs.  It  is 
now  thought,  however,  that  cutaneous  pain  arises  from  the 
stimulation  of  the  "free  nerve-endings." 

The  pain  spots  are  very  numerous  in  all  parts  of  the  skin. 
If,  with  the  point  of  a  fine  needle  or  a  stiff-pointed  bristle, 
we  explore  a  small  area  on  the  back  of  the  hand,  which  has 
been  previously  explored  for  pressure  spots,  we  shall  find 
that  the  pain  spots  outnumber  the  pressure  spots  very  greatly. 
There  may  be  over  one  hundred  pain  spots  to  the  square 
centimetre  in  some  parts  of  the  skin.  The  most  sensitive 
of  these  pain  spots  may  be  located  very  readily.  Care 
should  be  taken  to  put  the  point  of  the  needle  down  gently, 
and  always  with  the  same  intensity. 

Impulses  set  up  by  pain-stimulation  require  a  longer 
time  to  reach  the  cortical  centres  than  those  from  pressure- 
stimulation.  Or,  at  least,  the  latent  period,  or  the  period  of 
retardation  of  pain-sensations,  is  longer  than  in  that  of  pres- 
sure-sensations. Strike  the  back  of  the  hand  smartly  with 
a  lead-pencil.  Notice  that  the  sensation  of  pressure  appears 
first,  then  an  instant  later  the  sensation  of  pain.  This  sug- 
gests that  the  nerve-impulses  from  the  pressure  and  pain 
end-organs  are  conducted  to  the  brain  centres  along  different 
paths.  There  is  pathological  evidence  to  support  such  a/ 
theory. 

The  after-images  of  pain   remain  longer  than  those  of 


124  PSYCHOLOGY 

pressure,  and  there  is  much  less  adaptation  in  pain  than  in 
pressure.  We  do  not  "get  used"  to  pain-sensations  as  we 
do  to  pressure.  The  higher  intensities  of  pain  are  much 
more  insistent  than  other  sensations.  They  command  atten- 
tion and  crowd  out  the  other  contents  of  consciousness. 

The  sensation  of  pain  should  not  be  confused  with  the 
feeling  of  unpleasantness  which,  in  common  speech,  is  often 
designated  by  the  terms  "pain"  and  "painful."  This  con- 
fusion arises  from  the  fact  that  nearly  all  pain-sensations 
are  unpleasant.  While  it  is  exceedingly  unpleasant  to  lose 
one's  purse,  there  is  necessarily  no  pain-sensation  involved 
in  the  experience,  although  we  commonly  speak  of  it  as 
'"painful."  But  pain  as  a  sensation  and  pain  as  a  feeling 
are  entirely  different  experiences..  We  shall  refer  to  this  dis- 
tinction again  when  we  discuss  the  feelings. 

Sensations  of  Cold  and  Warmth. — The  sensations  of  cold 
and  warmth  are  often  erroneously  thought  of  as  different 
degrees  of  a  single  sense.  They  are,  really,  distinct  sensa- 
tions of  entirely  different  qualities,  and  they  arise  from  .fhe 
stimulation  of  separate  nerve-endings.  The  tendency  to 
think  that  they  belong  to  the  same  sense  is  probably  aided 
by  the  fact  that  temperature,  as  a  physical  condition,  is  a 
single,  unbroken  continuum.  The  further  fact  that  the  sen- 
sation of  cold  seems  to  pass  gradually  into  the  sensation  of 
warmth  through  a  point  of  indifference,  or  zero,  augments  the 
tendency  to  think  of  them  as  different  degrees  of  the  same 
kind  of  sensation. 

Both  cold  and  warmth  sensations  appear  on  the  skin 
surfaces  in  the  same  punctiform  manner  as  do  pressure- 
sensations.  The  warm  spots  flrp  snmpwha.t  IP^  nnme-cmis 
than  the  cold_spots,  while  the  cold  and  pressure  spots  are  ^ 
about  the  same  in  number  fr>r  any  given  area.  If  a  blunt- 
pointed  stylus  of  metal,  having  a  temperature  of  15  degrees  C. 
(59  degrees  F.)  is  drawn  lightly  across  the  inner  surface  of 
the  forearm,  in  addition  to  the  pressure-sensation  sudden 
flashes  of  cold  will  appear.  (The  point  of  a  lead-pencil  will 


CUTANEOUS    SENSATIONS  125 

stimulate  some  of  the  more  sensitive  cold  spots.)  The  spots 
where  these  cold  sensations  appear  are  arranged  in  irregular 
groups  and  chains.  Sometimes  isolated  spots  may  be  found. 
A  curious  fact  is  met  with  when  the  stylus  is  heated  to  45 
degrees  C.  (113  degrees  F.),  or  above,  and  placed  upon  a  cold 
spot.  The  spot  will  respond  with  a  perfectly  definite  sensa- 

tion    of    Cold.      TVn'g    i'g    rqllf^    tVip    "parqdrmVql    spinsa|inn    of 


When  the  stylus  is  heated  to  from  37  degrees  C.  to  40  de- 
grees C.  (99  to  104  degrees  F.)  the  warm  spots  may  be  lo- 
cated. The  sensations  of  warm  seem  more  diffuse  and  are 
located  with  more  difficulty  than  cold-sensations.  They  also 
come  to  full  intensity  more  slowly  than  the  cold-sensations, 
which  appear  very  promptly  when  the  stimulus  is  applied. 
When  the  stylus  is  heated  to  50  degrees  C.  (122  degrees  F.)L  U*-^«-j 
the  pain  spots  respond  with  the  sensation  of  pain.  j 

The  so-called  "hot  sensation"  is  a  combination  of  warm 
and  cold  sensations,  while  "burning  hot"  is  a  combination 
of  warm,  cold,  and  pain.  "Biting  cold"  is  a  combination 
of  cold  and  pain._  These  complex  sensory  experiences  are 
aroused  when  surfaces  of  extreme  temperatures  (above  45 
degrees  C.,  or  113  degrees  F.;  or  below  12  degrees  C.,  or  53 
degrees  F.)  are  applied  to  the  skin.  It  is  a  common  obser- 
vation of  every-day  life  that,  under  certain  circumstances, 
we  often  momentarily  confuse  very  hot  and  very  cold.  A 
very  hot  water-pipe  may  be  sensed  at  the  first  instant  that 
the  hand  comes  in  contact  with  it  as  icy  cold.  The  follow- 
ing diagram  will  show  the  relations  of  cold,  warm,  and  pain 
sensations  to  each  other. 

Temperatures  of  from  30  degrees  C.  to  36  degrees  C., 
being  near  the  physiological  zero,  appear  to  the  skin  indiffer- 
ent or  neutral.  If  the  temperature  is  lowered  the  stages  of 
cool,  cold,  and  biting  cold  are  successively  passed  through. 
At  12  degrees  C.  the  sensation  of  pain  appears,  and  rises 
very  rapidly  with  further  decrease  of  temperature.  If  the 
temperature  is  gradually  raised  from  physiological  zero,  the 


126 


PSYCHOLOGY 


stages  of  lukewarm,  hot,  and  burning  hot  are  experienced. 
At  45  degrees  C.  cold  (paradoxical  cold)  is  added  to  the 
warm  sensations  and  continues  for  the  temperatures  above. 
At  50  degrees  C.  pain  is  added  to  the  complex  and  gives  the 


\ 


10 


40 


-50 


60 


FIG.  44. — Diagram  showing  the  relations  of  cold,  warm,  and  pain  sensations 
to  each  other.  The  figures  on  the  base  line  indicate  the  temperature  in 
centigrade. 

(From  Pillsbury's  "Essentials  of  Psychology,"  after  von  Frey.) 

experience  of  burning  hot.  Only  between  36  degrees  C.  and 
45  degrees  C.  is  the  warm  sensation  unmixed.  Likewise,  only 
between  30  degrees  C.  and  12  degrees  C.  are  the  cold 
sensations  unmixed. 

Sensations  of  cold  and  warmth  may  be  aroused  by  organic 
processes  within  the  body.  In  fever  and  chills,  temperature- 
sensations  are  set  up  by  pathological  organic  disturbances. 
They  may  also  be  aroused  in  emotional  experiences,  as  in 


CUTANEOUS   SENSATIONS  127 

fear,  shame,  etc.  The  application  of  certain  substances,  like 
mustard,  pepper,  menthol,  and  alcohol  to  the  skin  gives  sen- 
sations of  temperature. 

Adaptation  of  the  temperature  end-organs  to  cold  and 
warm  stimulation  is  very  marked.  We  easily  adapt  our- 
selves to  varying  degrees  of  temperature.  Different  parts 
of  the  bodily  surface  are  constantly  subjected  to  different 
temperatures,  as,  for  instance,  the  tongue  and  the  forehead, 
yet  the  experiences  of  temperature  arising  from  them  are 
not  different.  A  room  that  seems  warm  when  we  first  enter 
will  shortly  become  indifferent  if  we  remain.  Likewise  a 
room  that  seems  cold  at  first  appears  warmer  as  we  become 
accustomed  to  it.  It  seems  that  any  portion  of  the  skin  41  ^ 
may,  within  certain  limits,  become  temporarily  adapted  to 
different  temperatures  so  that  they  appear  indifferent.  Fill 
three  bowls  with  water  of  different  temperatures,  one  at  20 
degrees  C.  (68  degrees  F.),  one  at  30  degrees  C.  (86  degrees 
F.),  and  the  remaining  one  at  40  degrees  C.  (104  degrees  F.). 
The  water  at  30  degrees  will  feel  indifferent,  neither  warm 
nor  cold.  Place  one  hand  in  the  water  at  20  degrees  C.  and 
the  other  hand  in  the  water  at  40  degrees  C.  Leave  them 
there  two  minutes,  then  plunge  both  hands. in  the  water  at 
30  degrees  C.  This  will  feel  decidedly  warm  to  one  hand 
and  cold  to  the  other.  .To  explain  this  fact,  viz.,  that  the  }  •  , 
same  absolute  degree  of  temperature  in  the  stimulus  may  < 
sometimes  cause  the  sensation  of  cold  and  sometimes  the  )  f 
sensation  of  warm,  we  may  suppose  that  the  physiological  fjf\ 
zero,  or  indifference-point  of  the  skin,  has  been  raised  in  one 
case  and  lowered  in  the  other,  and  that  any  temperature 
above  the  physiological  zero  will  arouse  sensations  of  warm, 
while  any  temperature  below  the  physiological  zero  will 
arouse  the  sensations  of  cold. 

Recent  physiological  investigations  of  the  effect  of  sever- 
ing certain,  sensory  nerves  supplying  a  given  area  of  the 
skin  upon  the  cutaneous  sensations  of  that  area  show  con- 
clusively that  the  sensory  nerves  which  carry  impulses  from 


A 


128  PSYCHOLOGY 

the  subcutaneous  tissues  are  separate  from  the  sensory 
nerves  supplying  the  skin  surface.1  In  these  investigations 
i  the  radial  and  external  nerves  of  the  left  arm  were  cut,  and 
'  then  the  part  of  the  cutaneous  area  from  which  these  nerves 
lead  was  subjected  to  rigid  experimentation.  The  most  con- 
clusive resujt  was  tfrat^  while  practicallyall  the  superficial 
^cutaneous  sensations  were  lost,  the  subcutaneous  sensations 
of  heavy  pressure^ncTljajn ^  [di^l^che)^an^kirjLaE5theJ^seji- 
sations  were  not  destroyed  by  the  operation.  There  re- 
mained crude  localization  ofheavy  pressure,  but  no  dis- 
crimination of  two  points  or  the  shape  of  objects.  This  in- 
dicates, that  the  nerve-fibres  for  these  senses  run  with  the 
deeper-lying  motor  nerves.  The  psychological  implication 
points  to  the  complete  separation  of  the  subcutaneous  and 
cutaneous  senses. 

Careful  exploration  of  the  cutaneous  surface  during  the 
process  of  recovery  or  reuniting  of  the  severed  nerves  showed 
that  there  are  two  systems  of  cutaneous  senses.  During  the 
first  stage  of  recovery  cutaneous  pain  and  temperature  sen- 
sations from  extremes  of  heat  and  cold  (above  45  degrees  C., 
or  113  degrees  F.;  and  below  20  degrees  C.,  or  68  degrees  F.) 
returned.  There  was,  however,  during  this  stage  no  sensi- 
bility to  light  pressure,  or  to  moderate  degrees  of  tempera- 
ture between  25  degrees  C.  (77  degrees  F.)  and  40  degrees  C. 
(104  degrees  F.),  i.  e.,  no  warm  and  cold  sensations  of  low 
intensities  could  be  aroused,  although  the  higher  intensities 
of  cold  and  warm  were  present.  In  this  stage  of  recovery 
only  the  more  intense  stimuli  aroused  sensations.  This  sys- 
tem of  sensory  experiences  was  given  the  name  of  protopathic 
sensations.  Some  months  later,  as  recovery  proceededTan- 
other  set  of  sensations  appeared:  light  touch  and  moderate 
degrees  of  cold  and  warm  sensations  of  temperatures  rang- 
ing from  25  degrees  C.  to  40  degrees  C.  Accurate  cutaneous 
localization  and  ability  to  recognize  two  points  and  the  shape 

1  Rivers  and  Head:  "A  Human  Experiment  in  Nerve  Division,"  in  Brain, 
1908,  vol.  XXXI,  p.  323. 


CUTANEOUS   SENSATIONS  1 29 

of  objects  reappeared  with  this  group  of  sensations.  These 
were  called  the  epicritic  sensations.  The  protopathic  warm 
and  cold  were  punctiform,  while  the  epicritic  were  non- 
puijetiform.  The  protopathic  sensations  responded  only  to 
strong  intensities  of  stimulation,  while  the  epicritic  responded 
only  to  light  stimulation.  It  was  therefore  concluded  that 
the  protopathic  senses  were  more  rudimentary  and  not  so 
highly  developed  as  the  epicritic.  While  this  investigation 
adds  much  to  our  knowledge  of  the  cutaneous  sensations,  it 
is  doubtful  whether  it  proves  the  existence  of  two  distinct 
forms.  Franz1  has  shown  that  the  transition  from  the  pro-! 
topathic  to  the  epicritic  sensibilities  is  gradual.  It  may  well] 
be  that  the  so-called  epicritic  sensations  are  simply  refine- J 
ments  of  the  cutaneous  sensations. 

Certain  pathological  conditions  in  the  nerve-pathways  of 
the  spinal  cord  and  nerve-root  furnish  interesting  dissocia- 
tions of  the  cutaneous  sensations.  In  some  diseases  the  sen- 
sation of  pressure  from  more  or  less  definite  parts  of  the 
skin  surface  is  lost,  while  sensations  of  pain  and  temperature 
remain.  In  others  all  sensations  of  temperature  and  cuta- 
neous pain  are  destroyed  on  extended  areas,  leaving  the 
sensation  of  cutaneous  pressure  intact. 

1  Journal  of  Comparative  Neurology  and  Psychology,  1909,  vol.  XIV,  pp. 
107,  215. 


CHAPTER 


OLFACTORY  AND  GUSTATORY  SENSATIONS 

• 

OLFACTORY   SENSATIONS 

End-Organ. — The  sensitive  area,  regio  olfactoria,  for  the 
sense  of  smell  is  located  in  the  upper  part  of  the  nasal  cavity, 
somewhat  removed  from  the  air-currents  of  ordinary  breath- 
ing. Only  by  sniffing  can  the  full  force  of  the  olfactory 
stimuli  be  brought  to  the  sensory  nerve-endings.  The  regio 
olfactoria  is  hardly  as  large  as  the  surface  of  a  dime  (250  sq. 
mm.  in  each  nasal  chamber).  In  this  area  are  found  the 
sensitive  olfactory  cells,  lying  between  supporting  epithelial 
cells  and  bearing  tufts  of  from  six  to  eight  cilia  upon  their 
peripheral  ends.  Tljgse  cells  are^true^^rve-cens.upon  which 
the  stimulus  acts  direcj^y.  They  extend  to"  the  surface  tff 
the  limiting  membrane  through  which  the  cilia  pass  in  order 
to  be  exposed  to  the  olfactory  stimuli.  Any  abnormal  con- 
dition of  the  mucous  membrane  will  disturb  the  proper  func- 
tioning of  these  sensitive  cells.  A  severe  cold  in  the  head 
will  be  accompanied  by  almost  complete  loss  of  the  sense 
of  smell.  Catarrhal  conditions  of  the  nasal  passages  will 
impair  the  sensitivity  of  this  sense. 

The  fibres  from  the  sensitive  olfactory  cells  connect  with 
other  neurones  which  pass  to  the  olfactory  lobes,  the  lower 
brain  centre,  which  in  turn  sends  fibres  to  the  pvnis^ricinatLis 
of  the  hippocampal  lobes,  which  constitute  the  cortical  or 
higher  centre  for  the  olfactory  sense. 

The  Stimulus. — It_is  a  curion^  far!  that  we  dp  not  know 
definitely  what  the  stimulus  is  which  exciter  the^olfactorv^ 
cells  and  arouses  the  sensations  of  odor^  It  is  very  probable 

""" 


OLFACTORY  AND  GUSTATORY  SENSATIONS 


that  odoriferous  substances  reach  the  end-organs  in  gaseous 
form.     Substances  that  give  out  odor  must  therefore  emit^ 
small  gaseous  particles  which  reach  the  olfactory  region  and 
there  set  up  chemical  reactions,  which  differ  in  character 
with- the  different  substances.     The  variation  in  the  chemical 
reactions  would  then  (so  far  as  the  stimulus  is  concerned) 
account  for  the  differences  in 
olfactory   sensations.     This 
theory  does  not  help  us  very 
much,  for  the  different  chemi- 
cal reactions    set   up    on  the 
mucous  membrane  of  the  nasal 
surfaces   have   not   yet    been 
determined. 

Another    theory    proposes 
that  the  gaseous  particles  give 
off    very    short    ether-waves, 
caused  by  their  intramolecular 
vibrations,  and  by  means  of 
these  waves  stimulate  the  sen- 
sitive nerve-cells.     In  this  case  the  kind  of  olfactory  sensation 
aroused   would   depend   upon    the   character   of   the   intra- 
molecular vibrations,  which  in  turn  depend  upon  the  vibra- 
tions of  the  atoms  or  groups  of  atoms  within  the  molecule. 
It  has  been  discovered  that  certain  substances  having  similar 
molecular    structure    possess    similar    odors.     But,    on    the 
othernahd,  some  subsFances  with  widely  different  constitu- 
tions are  similar  in  odor.     At  present  it  is  impossible  to 
make  any  thoroughgoing  correlation  between  the  molecular 
structure  of  odoriferous  substances  and  the  qualities  of  ol- 
factory sensations.     However,   some  interesting  facts  have 
come  out  of  the  investigations  into  the  chemical  nature  of 
odorous  substances.     For  instance,  it  has  been  found  that 
practically  all  odorous  substances  contain  elements  belonging 
to  only  three  groups  in  the  periodic_system  of  classification 
(MendelelefTs  groups).     They  are^the  fifth,  sixth,  and  sev- 


FIG.  45. — Diagram  showing  cells  in 
re'gio  olfactoria:  a,  olfactory  cell, 
with  h,  projecting  hairs;  b,  sup- 
porting cells;  c,  nerve-fibre. 


V 
f\f 


PSYCHOLOGY  / 

enth  groups.  If  similar  substances  derived  from  the  elements 
of  one  of  these  groups  are  arranged  according  to  their  molec- 
ular structure,  their  odors  will  form  a  series  of  related  odors 
which  shade  off  from  one  to  the  other.  As  an  illustra- 
tion, we  may  arrange  fatty  acids  in  the  following  order: 
formic  (CH2O2) ;  acetic  (C2H4O2) ;  propionic  (C3H6O2) ;  butyric 
4H8O2);  valerianic  (C5Hi0O2);  caproic  (C6Hi2O2).  The 
dors  from  these  substances  are  similar,  but  change  gradu- 
ally as  we  pass  along  the  series.  The  higher  acids  formed 
from  these  elements  (stearic,  Ci8H36O2)  have  little  or  no 
odor.1  Chlorine,  bromine,  and  iodine  give  off  odors  that  can 
also  be  arranged  in  a  series  of  similar  experiences. 

Classification. — The  fact  that  we  know  so  little  about  the 
stimuli  has  stood  in  the  way  of  classifying  the  many  differ- 
ent olfactory  sensations.  The  number  of  elementary  olfac- 
tory qualities  is  unknown.  As  yet  no  satisfactory  classifica- 
tion has  been  made.  Whether  all  odors  may  be  reduced  to 
a  few  elementary  kinds,  or  whether  they  must  remain  as 
they  are  now,  a  chaotic  mass  of  sensory  experiences,  only 
the  future  will  reveal. 

The  classification  of  olfactory  sensations  into  two  kinds, 
agreeable  and  disagreeable,  is  based  upon  the  feelings  which 
accompany  the  sensations,  and  not  upon  the  quality  of  the 
sensations  themselves.  It  is  therefore  of  little  value. 

The  modification  of  the  Linnaeus  table  of  olfactory  groups 
by  Zwaardemaker  is  practically  the  only  classification  of 
odors  that  we  have  at  the  present  time: 

1.  Ethereal  Odors:    Fruits,  wine,  ether,  beeswax. 

2.  Aromatic   Odors:    Spice,  lavender    and    anise,  lemon, 
cedar  wood,  rosewood,  almond. 

3.  Fragrant  Odors:    Flowers,  vanilla,  balsam. 

4.  Ambrosial  Odors :     Musk  and  amber. 

5.  Alliaceous  Odors:    Onion,  asafoetida,  dried  fish,  chlo- 
rine, ipdineN 

laycraft,  B)iain,  1888,  p.  166;    1889,  p.  160.     Schafer's  "Text  Book  of 
Physiology,"  i90o\II,  p.  1254. 

V 


V* 


GUSTATORY   SENSATIONS  133 

Burned  substances,  tar,  gasoline, 
creosot 

7.  HjteinejOdors :    Cheese,  rancid  butter,  lactic  acid. 

8.  Repulsive    Odors:    Narcotics,  certain  insects. 

9.  Nauseous  Odors:    Decaying  animal  matter. 

The  list  is  not  complete.  There  are  many  odors  which 
will  not  go  under  the  nine  headings,  and  it  is  evident  that  the 
different  classes  are  not  elementary  in  nature.  At  present 
the  only  hopeful  indication  of  a  successful  classification  of 
the  olfactory  sensations  is  the  suggestion  that  substances  of 
a  similar  chemical  nature  give  similar  odors.  Something 
may  be  done  by  putting  together  in"  a  single  class  all  sensa- 
tions aroused  by  each  group  of  closely  related  chemical  sub- 
stances. By  working  over  the  field  carefully  the  fundamental 
uniformities  and  differences  in  the  qualities  of  olfactory  sen- 
sations may  be  discovered. 

Many  olfactory  stimuli,  besides  arousing  their  own  true 
olfactory  sensations,  excite  also  other  concomitant  sensa- 
tions which  are  blended  with  the  olfactory  sensations  and  are 
often  confused  with  them.  Ammonia,  for  instance,  affects 
all  parts  of  the  mucous  membrane  in  the  mouth  and  throat, 
giving  a  stinging  or  tingling  tactile  sensation  besides  the 
smell  proper.  Likewise,  nauseous  stimuli  arouse  the  sensa- 
tions of  nausea,  which  are  mixed  with  the  true  olfactory 
sensations.  In  the  study  of  olfactory  sensations  these  ac-  N 
companying  sensory  elements  must  be  analyzed  out  and/ 
disregarded. 

The  threshold  of  olfactory  sensations  is  very  Jow.  A 
hound  following  the  trail  of  game  or  his  master's  footsteps 
by  the  sense  of  smell,  a  bird-dog  discriminating  the  different 
odors  of  "live"  and  "dead"  birds,  suggest  the  delicacy  of 
this  sense.  Man's  olfactory  sense  is  not  so  acute  as  that  of 
the  dog,  but  nevertheless  it  is  sharp  enough  to  detect  slight 
traces  of  known  substances  too  small  to  give  chemical  reac- 
tions. Camphor,  i  part  to^  400,000..  and  musk,  i  part  to 
8TogQ1oo^can  bedetected  by  the  sense  of  smell.  In  order 


134  PSYCHOLOGY 

to  be  sensed  at  all,  substances  must  be  composed  of  mole- 
cules having  a  certain  minimum  weight.  There  is  some 
individual  variation,  but  for  most  persons  any  substance 
whose  molecules  possess  a  weight  less  than  those  of  prussjc 


Adaptation  to  olfactory  stimuli  takes  place  very  rapidly. 
soon  fail  to  notice  the  odor  of  a  badly  ventilated  room. 
dors  that  are  very  marked  at  first  gradually  fade  out  if  the 
stimulus  is  continued.  If  camphor-gum  is  held  to  the  nos- 
trils for  a  few  minutes  the  decrease  in  the  intensity  of  the 
odor  can  be  noticed  before  the  end  of  the  first  minute.  If  the 
stimulus  is  allowed  to  act  long  enough,  it  will  become  in- 
odorous. One  laboratory  subject  gave  the  following  results: 
asafoetida  became  odorless  in  i  minute  and  17  seconds;  pep- 
permint in  6  minutes;  heliotrope  in  less  than  a  minute;  cam- 
phor in  i  minute  and  34  seconds;  iodine  in  54  seconds. 

This  adaptation  of  sense-organs  to  continued  stimulation 
has  sometimes  been  attributed  to  fatigue.  But  whether  we 
have  to  do  with  a  positive  process  of  adaptation  or  a  nega- 
tive one  of  fatigue  is  difficult  to  determine. 

The  fact  that,  when  the  olfactory  sense-organs  become 
adapted  to  a  certain  odor,  certain  other  odors  also  fail  to 
arouse  sensation,  while  others  are  sensed  without  impair- 
ment, indicates  that  different  olfactory  stimuli  have  similar 
physiological  effects.  This  sameness  of  physiological  effect 
might  very  well  be  taken  as  a  suggestion  for  the  classification 
of  odors.  Odors  which  have  the  same  effect  in  fatiguing  or 
adapting  the  sense-organ  might  be  considered  as  belonging 
to  the  same  class.  If  the  nose  is  fatigued  for  iodine,  it  be- 
comes thereby  fatigued  also  for  alcohol,  heliotrope,  and  pos- 
sibly other  odors,  while  the  odor  of  ethereal  oils  is  not  less- 
ened at  all. 

It  may  be  that  the  olfactory  nerve-endings  are  differenti- 
ated, and  that  a  given  stimulus  acts  upon  only  one  kind  of 
end-organ,  without  affecting  others.  The  phenomena  in 
partial^anosmia,  a  pathological  condition  in  which  the  sub- 


-V 

vor 


SENSATIONS  13 

ject,  while  possessing  in  other  respects  normal  olfactory  sen- 
sations, is  lacking  in  ability  to  sense  certain  odors,  point 
also  to  differentiated  end-organs.  It  is,  however,  improb- 
able that  certain  nerve-endings  are  set  apart  for  a  certain 
kind  of  stimulus  alone;  rather,  if  there  is  differentiation,  it  is 

'simply  that  certain  nervous  elements  in  the  olfactory  region 
are  more  sensitive  to  some  odors  than  to  others. 

Many  of  the  great  variety  of  odors  which  we  experience 
are  the  result  of  combination  and  fusion  of  odors.  Odors 
may  combine  in  such  a  way  that  we  are  able  to  detect  the 
presence  of  each  one  in  the  combined  result.  Or  odors  may 
fuse  and  form  a  new  odor,  in  which  the  component  parts  are 
not  detected.  Under  some  circumstances  certain  odors  will 
not  combine  or  fuse,  but  rather  suppress  each  other.  For 
instance,  the  odor  of  carbolic  acid  suppresses  the  odor  of 
putrefaction^  If  two  different  odors  which  suppress  or  "  com 
pensate"  each  other  are  presented  through  the  olfactometer 
one  to  each  nostril  at  the  same  time,  the  phenomenon  of 
rivalry  is  set  up.  We  sense  first  one  and  then  the  other 
alternately.  Contrast  effects  are  also  present  among  odors. 
For  instance,  it  has  been  found  that  after  smelling  cedar 
wood  for  a  short  time  the  odor  of  india-rubber  becomes  notice-  ^ 
ably  more  distinct.  / 

Sensations  of  smell  are  very  rich  in  associations.     They       c 
are  also  effective  in  arousing  feelings,  moods,  and  emotional    J* 
attitudes.     The  fact  that  incense  plays  an  important  part  v^ 
in  certain  religious  rites  and  ceremonies  is  interesting  in  this 
connection.     The  aesthetic  value  of  perfumes  is  due  to  the 
relation  of  sensations  of  odors  and  the  feelings. 

It  is  thought  that  the  sense  of  smell  is  degenerating  in 
man.  It  is  pointed  out  that  man's  sense  of  smell  is  much 
less  acute  than  that  of  the  lower  animals,  and  that  while  the 
olfactory  lobes,  the  lower  centre  for  smell,  make  up  the  larger 
part  of  the  brain  in  some  of  the  lower  animal  forms,  in  man 
they  have  dwindled  into  insignificance.  Certainly,  in  man, 
the  importance  of  this  sense  has  become  relatively  less  promi- 


136  PSYCHOLOGY 

nent.  To  the  animal  that  must  track  its  prey  or  scent  the 
presence  of  its  enemies,  or  find  its  mate,  it  is  the  chief  food- 
getting  and  race-propagating  sense.  But  man  has  risen 
above  this  primitive  method  of  sense-guidance,  and  has  come 
to  depend  more  and  more  upon  the  more  highly  developed 
senses.  The  olfactory  sensations,  however,  still  stand  guard 
over  the  selection  of  foods  and  aid  in  the  detection  of  noxious 
and  injurious  surroundings.  They  also  contribute  no  incon- 
siderable part  to  the  character  of  what  we  ordinarily  con- 
sider the  sense  of  taste.  Taste  and  smell  are  so  closely 
related  that  without  critical  psychological  analysis  we  fail 
to  discriminate  the  elements  supplied  by  the  sense  of  smell 
to  the  complexes  which  masquerade  under  the  name  of  taste. 

GUSTATORY  SENSATIONS 

On  account  of  the  very  close  relation  between  the  sen- 
sory experiences  which  come  from  the  nose  and  the  mouth, 
and  because  the  tongue  surface  is  also  capable  of  giving  rise 
to  sensations  of  pressure,  temperature,  and  pain,  as  well  as 
gustatory  sensations,  we  rarely  ever  experience  the  quality 
of  taste  alone.  Our  so-called  sensations  of  taste  are  com- 
plexes of  taste  proper,  smell,  tactile,  temperature,  and  in 
some  cases  weak  pain  sensa-tions^  It  is  a  common  observa- 
tion that  while  we  are  suffering  from  a  severe  cold  in  the 
head  we  lose  most  of  our  taste-sensations.  It  is  not  taste 
proper,  however,  but  the  odor  of  food  substances  which  is 
lost,  and  which  we  have  confused  with  taste  because  it  blends 
so  closely  with  it.  All  substances  taken  into  the  mouth 
excite  tactile  sensations.  Temperature  is  usually  present, 
and  a  few  substances,  like  charged  beverages,  arouse  slight 
pain-sensations.  So,  ordinarily,  what  we  accept  as  taste  is 
a  compound  of  several  kinds  of  sensations.  It  is  a  difficult 
task  to  analyze  out  of  these  complexes  the  true  sensations  of 
taste. 

If  the  nostrils  are  stopped  so  that  no  air  passes  through 
them,  one  is  unable  to  taste  the  difference  between  many  dif- 


OLFACTORY  AND  GUSTATORY  SENSATIONS     137 

ferent  substances,  such  as  tea,  coffee,  solutions  of  quinine, 
etc.  The  subject  should  be  blindfolded  and  the  solutions 
should  be  of  equal  strength,  but  not  strong  enough  to  arouse 
tactile  sensations  by  the  astringent  quality  of  the  solutions. 
The  student  will  be  surprised  to  find  how  blunted  apparently 
the  sense  of  taste  is  when  smell  is  eliminated.  Much  of  the 
flavor  of  fruits,  the  bouquet  of  wines,  and  many  other  so- 
called  taste  qualities  are  contributed  by  the  sense  of  smell. 

End-Organ. — The  end-organs  for  gustatory  sensatjojwrSxe 
the  taste-buds  found  chiefly  in  the  papillae  of  the^-tfmgue,  but 
also  on  the  surface  of  the  soft  palate,  the  fauces,  and  epiglot> 
tis,  and  evenjn  the  larynx.  JTaste-buds  are  small  oval  bodies 
resembling  a  bud  in  structure  and  occupying  little  pit-like 
cavities  in  the  epithelium.  These  cavities  open  out  into 
the  mouth  through  small  apertures  called  "gustatory  pores." 
Through  these  pores  food  substances  in  solution  enter  and 
stimulate  the  taste-buds.  The  highly  modified  epithelial 
cells  which  make  up  the  taste-bud  are  of  two  kinds,  the 
supporting  cells — long  and  tapering — and  the  gustatory  cells 
which  occupy  the  more  central  part  of  the  taste-bud.  The 
gustatory  cell  is  a  spindle-shaped  cell  whose  outer  end  termi- 
nates in  a  fine,  hair-like  process  which  projects  through  the 
gustatorvjgojp.  It  was  formerly  thought  that  its  inner  end 
was  continuous  with  a  true  nerve-fibre,  but  this  is  not  true. 
The  sensory  nerve-fibres  enter  the  base  of  the  taste-bud 
and,  dividing  into  many  branches,  end  about  the  body  of 
the  gustatory  cell.  Outside  the  taste-buds  are  found  other 
nerve-endings  which  minister  to  the  cutaneous  sensations  of 
pressure,  cold,  warmth,  and  pain,  which  are  also  present  in 
the  mouth  surfaces.  On  the  tongue  the  taste-buds  are  found 
on  the  sides  of  the  circumvallate  papillae,  in  the  fungiform 
papillae,  and  in  the  furrows  between  them.  The  filiform 
papillae  do  not  contain  taste-buds.  It  is  estimated  that 
there  are  from  100  to  200  taste-buds  in  each  one  of  the  cir- 
cumvallate papillae. 

The  gustatory  cells  are  without  doubt  the  sensory  end- 


138 


PSYCHOLOGY 


organs.  The  hair-like  processes  are  stimulated  by  the  solu- 
ble substances.  The  impulses  set  up  are  communicated 
through  the  body  of  the  cell  to  the  endings  of  the  sensory 
fibres  which  terminate  about  these  cells. 

Gustatory  Nerves  and  Brain  Centres.— 
The  back  part  of  the  tongue,  the  location 
of  the  circumvallate  papillae,  is  supplied  by 
sensory  fibres  from  the  glosso-pharyngeal 
or  ninth  cranial  nerve,  while  the  front  part 
receives  sensory  fibres  from  the  lingual 
branch  of  the  trigeminal  or  fifth  nerve.  So 
far  as  can  be  determined,  the  cortical  cen- 
tres for  gustatory  sensations  are  in  the  inner 
sides  of  the  hemispheres  in  the  hippocampal 
lobes,  near  but  posterior  to  the  olfactory 
centres. 

Stimulus. — All  gustatory  stimuli  must 
be  soluble.  A  perfectly  insoluble  substance 
is  tasteless.  It  does  not  follow,  however, 
that  all  soluble  substances  have  taste;  some 
do  not.  A  sapid  substance,  not  in  liquid 
form,  may  dissolve  in  the  saliva  after  being 
taken  into  the  mouth,  and  -so  reach  the 
taste-buds,  where  it  sets  up  a  chemical 
change.  There  seems  to  be  no  consistent 
relation  between  the  chemical  nature  of  substances  and  the 
taste-sensations  which  they  arouse.  Substances  of  very  dif- 
ferent chemical  constitution  arouse  the  same  taste-sensations. 
The  question  of  whether  mechanical  stimulation  of  the 
tongue  arouses  taste-sensations  is  in  dispute.  Apparently 
vague  sensations  of  taste  can  be  aroused  by  tapping  the  tip 
of  the  tongue.  There  is  no  doubt  of  the  fact  that  electric 
currents  passed  through  the  tongue  excite  taste-sensations. 
The  positive  pole  of  a  battery  tastes  decidedly  sour  and  the 
negative  pole  is  slightly  bitter.  Whether  this  is  due  to  the 
direct  effect  of  electricity  upon  the  taste-buds,  or  is  the 


FIG.  46.— Diagram 
showing  a  taste- 
bud  and  the 
nerve-endings :», 
nerve  -  fibre,  a, 
gustatory  pore; 

b,  gustatory  cell; 

c,  supporting  cell. 
(Retzius.) 

(From  Quain's  "Ele- 
ments of  Anatomy.") 


OLFACTORY   AND    GUSTATORY   SENSATIONS  139 

result  of  electrolysis  in  the  saliva  which  might  free  acid  and 
alkaline  ions,  is  not  known. 

Classification  of  Gustatory  Sensations. — The  gustatory 
sensations  may  all  be  reduced  to  four  elementary  or  simple 
sensations : 

1.  Sweet. 

2.  Sour. 

3.  Bitter. 

4.  Saline. 

Alkaline  and  metallic  sensations  have  been  proposed,  also, 
as  elementary  taste-sensations,  but  they  are  thought  by  some 
experienced  observers  to  be  compounds:  alkaline  being  a 
combination  of  salt  and  sweet,  and  metallic  of  salt  and  sour. 
Even  sweet,  sour,  bitter,  and  saline  sensations,  as  we  know 
them  in  our  ordinary  taste  experiences,  are  not  simple  or 
pure.  The  sensation  aroused  by  salt  has,  in  addition  to  its 
taste,  a  slight  burning  sensation  which  is  tactual  in  its  origin. 
The  tactile  sensation  may  be  aroused  alone  by  solutions  of 
salt  too  weak  to  arouse  the  taste  of  salt.  Sour  or  acid  sen- 
sations have  an  astringent  quality  which  is  not  due  to  taste. 
Sweet  has  a  smooth,  almost  oily  quality,  which  can  be  iso- 
lated, as  can  the  other  non-gustatory  qualities  mentioned, 
by  applying  the  stimuli  to  tasteless  regions  of  the  mouth — 
the  middle  of  the  tongue  or  the  hard  palate. 

Whether  the  four  elementary  gustatory  sensations  have 
special  taste-buds  in  each  case  is  not  known.  We  do  not 
know  definitely  whether  an  individual  taste-bud  will  respond 
to  only  one  or  to  four  kinds  of  stimulation,  and  so  produce 
the  nerve-excitation  for  one  or  for  four  kinds  of  sensation. 
We  do  know  that  there  is  a  partial  surface  differentiation  of 
the  tongue  for  the  four  taste  qualities.  For  instance,  the 
circumvallate  papillae  at  the  base  of  the  tongue  are  more 
sensitive  to  bitter  than  to  the  other  qualities.  The  tip  of 
the  tongue  is  more  sensitive  to  sweet  and  salt  and  less  sen- 
sitive to  sour  and  bitter,  while  the  sides  of  the  tongue  are 
especially  sensitive  to  sour.  (The  central  portion  of  the 


. 

in  adults  has  been  found  completely  lacking  in  taste- 
sensations,  although  possessing  those  of  the  pressure,  ther- 
mal,  and  pain  senses.)  Some  experimental  results  of  stimu- 
lating  individual  papillas  with  sweet,  sour,  bitter,  and  saline, 
indicate  that  the  taste-buds  may  be  differentiated.  It  has 
been  found,  for  instance,  that  some  of  the  papillae  respond 
to  only  one  kind  of  stimulation,  others  to  two,  others  to 
three,  and  still  others  to  all  four.1  Where  a  single  papilla 
gives  out  only  one  kind  of  sensation,  it  seems  probable  that 
it  contains  taste-buds  of  one  kind  only.  Pathological  cases 
of  partial  ageusia,  or  loss  of  taste,  have  been  reported  in 
which  one  or  two  of  the  taste  qualities  are  lacking,  while  the 
others,  are  not  affected.  Certain  drugs  will  destroy  some  of 
the  elementary  gustatory  sensations  without  interfering  with 
the  others.  The  leaves  of  the  plant  gymntmn.  .y-y/^y/r^  will, 
when  chewed,  cause  the  loss  of  sensations  of  sweet  and  bit- 
ter, while  salt  and  sour  remain.  If  a  proper  solution  of  co- 

i  caine  is  placed  upon  the  tongue  it  will  affect  the  taste-sensa- 
tions  separately:  first  bitter  is  lost,  then  sweet,  then  salt,  and 

1  finally  sour.  Another  fact  of  interest  in  this  connection  is 
that  some  substances  will  arouse  different  tastes  on  different 
parts  of  the  tongue;  sodium  sulphate-4fi-ftaAty-^e-4he  _tip  and 
bitter  to  the  ba^e^eftKe^tongue.^while  a  certain  form  of  sac- 
to  the  tip  and  bitter  to  the  posterior  part  of 


} 


e  tongue.     All  these  facts  would  not  be  difficult  to  explain 
if  we  were  certain  that  the  taste-buds  are  differentiated,  so 
^hat  a  single  bud  responds  with  only  one  kind  of  sensa- 
^  tion. 

Retardation. — The  initial  period  of  retardation  differs 
slightly  for  the  four  qualities  of  taste-sensations.  Salt  is  the 
quickest  and  bitter  the  slowest  in  responding  after  the  stim- 
ulus is  applied.  This  may  be  due  either  to  the  chemical 
nature  of  the  stimulus,  or  to  the  manner  in  which  the  end 
organs  respond,  or  even  to  the  central  cortical  processes. 

1Oehrwall:  Skandinavisches  Archiv  f.  Physiol.,  1890,  II,  p.   i.     Kiesow: 
"  Wundt's  Philosoph.  Studien,"  1898,  XIV,  p.  591. 


OLFACTORY  AND   GUSTATORY   SENSATIONS  141 

Mixtures,  Contrasts,  Adaptation. — The  mixing  of  two 
taste-stimuli  may  result,  in  some  cases,  in  the  sensations  re- 
maining separate  and  distinct  from  each  other,  although 
both  are  present  in  consciousness;  in  others,  the  sensations 
may  alternate,  first  one  and  then  the  other  appearing,  or 
they  may  tend  to  neutralize  or  compensate  each  other.  Salt 
and  bitter,  if  not  too  intense?  may  exist  side  by  side.  If, 
however,  the  intensities  of  taste-sensations  are  high,  there 
is  a  tendency  toward  rivalry.  The  neutralization  or  com- 
pensation of  tastes  is  very  familiar:  the  taste  of  sugar  will 
neutralize  the  bitter  taste  of  coffee,  or  the  sour  taste  of  claret. 
There  seems,  however,  rarely  to  be  a  complete  neutralization 
between  compensating  tastes:  The  nearest  approach  is  that 
set  up  between  sweet  and  salt.  If  salt  is  added  to  a  weak 
sweet,  an  insipid,  flat  taste,  neither  sweet  nor  salt  results. 
which  amounts  almost  to  the  absence  of  taste-sensation. 
Compensation  is  least  noticeable  between  sweet  and  sour, 
while  salt  and  bitter,  sour  and  bitter,  sour  and  salt,  and 
sweet  and  bitter  manifest  it  in  increasing  degrees  as  we  pass 
from  one  pair  to  the  next.  There  is  sometimes  a  marked 
degree  of  neutralization  between  tastes  and  smells;  the  nau- 
seating odor  of  castor-oil  is  offset  by  the  sour  taste  of  lemon- 
juice,  or  the  bitter  taste  of  quinine  is  partially  neutralized  by 
the  aromatic  odor  of  essence  of  orange-peel. 

Contrast  effects  are  also  present  in  gustatory  sensations. 
The  sour  taste  of  fruit  appears  more  intensely  sour  after 
honey  has  been  taken  into  the  mouth.  Contrasts  (both 
simultaneous  and  successive)  may  be  observed  between  salt 
and  sour,  and  salt  and  sweet.  If  the  tip  of  the  tongue  is 
stimulated  first  with  a  salt  solution,  then  thoroughly  rinsed 
and  dried,  a  very  weak  sohition  of  sweet,  which  cannot  be 
tasted  normally,  tastes  decuJedly  sweet.  Even  distilled 
water,  which  is  ordinarily  tasteless,  will  appear  sweet  after 
salt  stimulation.  Salt  appears  to  bring  out  the  sweet.  The 
same  effect  may  be  obtained  by  simultaneous  stimulation  of 
the  two  sides  of  the  forward  part  of  the  tongue:  salt  applied 


142  PSYCHOLOGY 

on  one  side  will  increase  the  effect  of  a  weak  solution  of  sweet  ,> 
on  the  other.  Contrast  effects  in  bitter  have  not  been  estab- 
lished. A  bitter  sensation  which  lies  just  below  the  threshold 
cannot  be  brought  out  by  simultaneous  stimulations  of  sweet, 
sour,  or  salt. 

Adaptation  of  the  sense-organs  of  taste  is  not  as  marked 
as  in  the  case  of  the  olfactory  sense.  It  is,  however,  notice- 
able in  our  every-day  experiences.  Food  which  at  first  seems 
very  sweet  will,  if  we  continue  to  eat  it,  decrease  in  intensity. 
A  solution  of  salt  will  appear  less  salty  as  we  continue  to  taste 
it.  It  may  be  that  some  of  the  successive  contrast  effects 
mentioned  above  are  due  to  adaptation.  When,  for  in- 
stance, the  sour  of  fruit  is  increased  after  honey  is  eaten,  the 
adaptation  of  the  sense-organs  to  the  honey  may  make  them 
less  able  to  taste  the  sweet  in  the  fruit  and,  consequently,  its 
acid  quality  will  stand  out  more  plainly. 

Threshold.  —  The  tgTnppra-*"yp  ^1  fi^P1'^  *\uftsta.nres  affects 
the  threshold  of  gustatory  sensations.  Extremes  of  cold  and 
warm  lessen  the  sensitiveness  of  the  taste-organs.  To  get  the 
maximum  effect,  taste-stimuli  should  be  of  moderate  tem- 
peratures.  Hot  soups  and  cold  beverages  sacrifice  the  true 
gustatory  sensations,  and  minister  to  the  tactile  and  tem- 
perature-sensations in  the  mouth,  and  the  olfactory  sensa- 
tions in  the  nose.  The  total  complex  effect  may  be  enhanced, 
but  taste-sensations  are  lessened  thereby.  What  the  weak- 
est sensation  of  taste  is  for  any  given  substance  can  be  de-  ^£ 


termined  only  by  the  strength  of  solution  necessary  to 
a  just  perceptible  taste-  sensation.  The  salt  of  sodium  cmp- 
ruje-Qari  he  tasted  upon  the  tip  of  the  tongue  when  the  solu- 
tion is  0.25  gm.  to  100  c.c.  of  water;  sweet_of_sugar  on  the 
tip  of  the  tongue,  0.50  gm.  to  ioo_c.c.  of  water;  bitter  of 
quinine  on  the  base  of  the  tqngue,  0.00005  grn.  jtCLlogic.c.^  of 
water;  sour  of  hydrochloric  acid  on  the  sides  of  the  tongue, 
0.007  S111-  to  TOO  c.c.  of  wafer.  There  are  some  individual 
variations  among  different  subjects,  but  these  results  hold 
for  any  one  having  a  fairly  acute  sense  of  taste. 


OLFACTORY   AND   GUSTATORY   SENSATIONS  143 

Complexes. — In  the  beginning  of  this  discussion  we  called 
attention  to  the  blending  of  sensations  of  taste,  smell,  tactile, 
temperature,  and  pain  sensations.  Before  leaving  the  sub- 
ject we  may  again  call  attention  to  the  need  of  critical  psy- 
chological analysis  when  dealing  with  the  so-called  tastes  of 
every-day  life.  Some  of  these  so-called  tastes  are  really  not 
tastes  at  all.  The  pungent  "  tastes  "  of  spices  are  almost  alto- 
gether odors,  astringent  tactile  sensations,  and  temperature- 
sensations,  sometimes  mixed  with  slight  intensities  of  pain. 
Tea  and  coffee  owe  their  distinguishing  characters  to  odor 
and  astringent  tactile  sensations.  Many  food  substances, 
/like  nuts  and  vegetables,  are  distinguished  in  the  mouth  by 
/their  consistency,  which  appeals  to  pressure-sensations.  Pep- 
permint is  hardly  a  taste  at  all;  there  is  very  little  left  when 
the  sensations  of  cold  and  smell  are  eliminated.  The  so- 
called  oily  tastes  are  tactile  in  nature. 

This  tendency  of  sensations  to  blend  and  combine  into 
complex  experiences  is  present  everywhere  in  the  sensory 
realm,  but  the  taste  and  smell  sensations  furnish  such  a 
striking  illustration  of  the  coalescing  nature  of  consciousness 
that  it  is  well  to  emphasize  the  point  at  this  time. 


VII 

/*N 

AUDITORY  SENSATIONS 

Auditory  sensations  belong  to  two  great  groups:  sensa- 
tions of  noises  and  sensations  of  tones.  Noises  are  caused 
by  the  irregular,  non-periodic  vibrations  of  air  particles  set 
up  by  objects  in  the  outer  world.  Tones,  on  the  other  hand, 
are  caused  by  regular,  recurrent,  periodic  vibrations  of  air 
particles.  Here,  as  in  all  the  other  sense  realms,  the  real 
elementary  qualities  of  sensations  are  obscured  in  every-day 
experience  by  the  combinations  and  complexes  in  which  they 
appear.  For  instance,  the  apparently  simple  sound  of  a 
single  piano  note  is  made  up  of  at  least  two  or  more  discrim- 
inable  tonal  sensations,  which  we  can  isolate  with  a  little 
practice  in  careful  observation.  In  order,  then,  to  get  at  the 
component  elements  of  our  experiences  of  sound,  we  must 
analyze  these  experiences  critically.  In  the  case  of  auditory 
sensations  we  can  make  a  much  larger  use  of  the  knowledge 
of  physics  than  we  have  heretofore.  Happily,  the  physicist's 
knowledge  of  the  nature  of  the  stimuli  for  the  sense  of  hear- 
ing— resounding  bodies  and  the  air-waves  which  they  propa- 
gate— is  of  great  value  in  breaking  up  the  compounds  of 
auditory  consciousness  into  its  elements.  We  are  further 
aided  by  the  advanced  stage  of  physiological  and  anatomical 
knowledge  of  the  inner  ear — the  sense-organ  of  hearing. 

End-Organ. — The  inner  ear  is  a  twofold  organ  of  sense. 
One  part  of  it,  the  cochlea,  transforms  air-vibrations  into 
sensations  of  sound;  another  part,  the  vestibule  and  the 
semicircular  canals,  yields  sensations  of  movement  and 
equilibrium.  This  latter  part  we  have  already  treated  under 
kinaesthetic  sensations.  It  is,  therefore,  the  cochlea,  the 
winding  snail-shell  of  the  ear,  that  commands  our  attention 

144 


AUDITORY   SENSATIONS 


145 


as  the  organ  of  hearing  proper.  The  outer  ear,  composed 
of  the  pinna  and  the  external  auditory  canal,  and  the  middle 
ear  [shut  off  from  the  external  ear  by  the  tympanic  mem- 
brane, or  drum,  and  containing  small  ear-bones  (malleus, 
incus,  and  stapes)  controlled  by  two  small  muscles  (tensor 


FIG.  47. — Semidiagrammatic  section  through   the   right  ear   (Czermak).     G, 
external  auditory  canal;    T,  tympanic  membrane;  P,  tympanic  cavity;  o, 
fenestra  ovalis;    r,  fenestra  rotunda;  B,  semicircular  canal;   S,  cochlea;  Vt, 
scala  vestibuli;  Pt,  scala  tympani;  E,  Eustachian  tube. 
(From  Howell's  "Text-Book  of  Physiology.") 

tympani  and  stapedius)]  simply  furnish  the  means  of  trans- 
mitting air-vibrations  from  the  outer  world  to  the  auditory 
nerves  in  the  cochlea  of  the  inner  ear.  The  middle  ear  opens 
into  the  upper  and  back  part  of  the  mouth-cavity  through 
the  Eustachian  tube,  whose  function  it  is  to  equalize  the  air- 
pressure  on  both  sides  of  the  tympanic  membrane. 

The  outer  shell  or  pinna  of  the  ear  receives  the  air-waves 
and  conducts  them  inward  through  the  external  auditory 
canal.  It  is  probable  that  the  air-waves  are  modified  some- 
what by  the  structure  of  the  outer  ear,  the  shorter  waves 


146  PSYCHOLOGY 

being  strengthened  and  the  longer  waves  lessened  in  ampli- 
tude.    The  ear-drum  is  a  thin  membrane,  slightly  funnel- 
shaped,  with  its  apex  turned  inward.     The  three  ear-bones, 
lor  ossicles,  articulated  together,  stretch  across  the  cavity  of 
I  the  middle  ear  from  the  ear-drum  to  the  oval  window, of  the 
/inner  ear,  into  which  one  of  them — the  stapes — fits.     The 
two  small  muscles  which  attach  to  the  ear-bones  control, 
through  the  lever-like  action  of  the  bones,  the  tension  of 
the  ear-drum,  thus  adjusting  it  to  a  large  range  of  tonal 
vibrations.     It  is  supposed  by  some  that  air-vibrations  are 
communicated   from   the   ear-drum   to  the  fluid — the  peri- 
lymph — of  the  inner  ear  hy__rneg.na.  of  the  me.rh anical  piston- 
like  action  pf  the  gar-hones,  which  act  in  such  a  manner  that 
the  vibrations  of  the  ear-drum  are  intensified  at  the  oval 
window  of  the  vestibule.     But  cases  of  persons  whose  ear- 
bones  have  been  destroyed  or  removed  by  surgical  operation, 
and  who  can,  nevertheless,  hear  sufficiently  well  to  carry  on 
a  conversation,  prove  that  the  vibrations  may  be  carried 
across  the  middle  ear-cavity  without  the  aid  of  the  ossicles. 
Vibrations  may  also  reach  the  inner  ear  through  the  bones 
f     of  the  skull.     If  the  ears  are  stopped,   a  feebly  sounding 
I  tuning-fork  cannot  be  heard ;  but  if  its  base  is  pressed  against 
-^l^he  head,  it  can  be  heard  distinctly.     The  ticking  of  a  watch 
c"    which  cannot  be  heard  with  the  ears  stopped  becomes  audi- 
ble when  placed  between  the  teeth. 

The  inner  ear  is  composed  of  the  bony  labyrinth,  an 
intricate  chamber  hollowed  out  of  the  temporal  bone.  Within 
the  chamber  lies  the  membranous  labyrinth,  a  closed,  irregu- 
larly shaped  sac  which  fits  very  loosely  to  the  walls  of  the 
bony  chamber,  and  is  separated  from  it  by  the  perilymph, 
the  fluid  which  fills  the  spaces  outside  the  sac.  The  sac 
itself  is  filled  with  a  fluid  called  the  endolymph. 

The  vestibule  is  the  central  cavity  of  the  bony  labyrinth 
and  opens  out  into  the  semicircular  canals  behind  and  into 
the  cochlea  in  front.  It  communicates  with  the  middle  ear 
by  means  of  the  oval  window  (fenestra  ovalis],  into  which 


AUDITORY   SENSATIONS 


the  base  of  the  stapes  fits.  From  the  lower  part  of  the 
cochlea  another  opening  (fenestra  rotunda)  closed  by  a  thin 
membrane  leads  into  the  middle  ear.  The  parts  of  the  mem- 
branous labyrinth  are  the  utriculus,  which  opens  into  the 


Ductus  Endolymphaticus 
FIG.  48. — The  membranous  labyrinth  (enlarged). 

semicircular  canals,  the  sacculus  and  its  indirect  connection 
with  the  utriculus,  and  the  membranous  cochlea. 

The  bony  cochlea,  a  spiral  canal  which  winds  two  and 
one-half  times  about  its  axis,  or  modiolus,  contains  three 
membranous  canals:  the  scala  vestibuli,  the  scala  tympani, 
and  the  scala  media. 

The  scala  vestibuli  communicates  with  the  perilymph  in 
the  vestibule  and  carries  the  vibrations  set  up  there  along  its 
length  to  the  apex  of  the  cochlea,  where  it  communicates 
through  a  small  opening  with  the  scala  tympani,  which  de- 
scends to  the  base  of  the  cochlea.  Here  the  scala  tympani 
ends  at  the  round  window.  If  the  vibrations  which  have 
travelled  the  length  of  these  tubes  have  not  already  spent 
their  force,  they  are  cushioned  against  the  flexible  membrane 
of  the  window.  It  is  supposed  that  this  acts  as  a  safety 
device  by  lessening  the  force  of  the  too  powerful  vibrations, 


148 


PSYCHOLOGY 


which  might  injure  the  delicate  specialized  cell-structures  of 
the  inner  ear.  The  scala  media,  or  canal  of  the  cochlea,  lies 
between  the  scala  vestibuli  and  the  scala  tympani,  but  does 
not  communicate  with  them.  On  the  floor  of  the  scala  media 


C.  N. 


FIG.  49. — Longitudinal  section  of  the  cochlea.    S.V.,  scala  vestibuli;  S.T.,  scala 
tympani;  M,  scala  media;  G,  cochlear  ganglion;  C.N.,  cochlear  nerve. 

are  found  the  special  organs  of  hearing:  the  basilar  membrane, 
the  rods  of  Corti,  and  the  hair-cells.  About  these  specialized 
cells,  the  fibres  of  the  auditory  nerve  end.  The  canal  of  the 
bony  cochlea  is  partly  divided  into  upper  and  lower  halves 
by  a  bony  shelf.  The  basilar  membrane  stretches  from  the 
free  edge  of  this  shelf  across  to  the  outer  wall  of  the  cochlea 
and  so  makes  the  partition  complete  and  at  the  same  time 
forms  the  floor  of  the  scala  media,  upon  which  the  rods  of 
Corti  and  the  hair-cells  rest.  Another  membrane  (membrane 
of  Reissner)  stretches  from  the  bony  shelf  to  the  upper  wall 
of  the  canal  forming  the  roof  of  the  scala  media  and  separat- 
ing it  from  the  scala  vestibuli.  (See  Fig.  50.) 

The  basilar  membrane,  forming  the  floor  of  the  spiral 


AUDITORY   SENSATIONS 


149 


canal,  is  composed  of  short,  transverse  fibres,  which  reach 
from  the  shelf  to  the  outer  wall.  Due  to  the  fact  that  the 
spiral  shelf  becomes  narrower  as  it  ascends,  the  fibres  of 
the  basilar  membrane  become  longer  toward  the  apex  of  the 
cochlea.  The  number  of  basilar  fibres  is  estimated  at  24,000. 


Cochlear  :;•£} 
Nerve 


of  Corti  W/2-fastfar 
I  of  Corti      IMMembrane 


FTG.  50. — A  transverse  section  of  the  cochlear  tube. 

The  rods  of  Corti  form  two  rows  of  rod-like  cells,  which 
stand  upon  the  basilar  membrane,  and  since  the  outer  and 
inner  rods  lean  toward  each  other  and  unite  at  their  tops, 
they  enclose  a  tunnel  (canal  of  Corti)  which  extends  the 
whole  length  of  the  cochlea.  The  rods  of  Corti  are  com- 
puted to  be  9,500  in  number. 

The  hair-cells  lie  on  both  sides  of  the  rods  of  Corti.  They 
consist  of  rows  (one  inner  and  four  or  five  outer  rows)  of 
column-like  cells  which  run  parallel  to  the  rods  of  Corti. 
The  hair-cells  bear  short,  stiff,  hair-like  processes  upon  their 
upper  extremities. 

The  nerve-fibres  of  the  cochlear  branch  of  the  eighth  or 
auditory  nerve  pass  through  openings  in  the  bony  substance 
of  the  spiral  lamina  and,  entering  the  scala  media  at  the  base 


150 


PSYCHOLOGY 


of  the  hair-cells  and  rods  of  Corti,  they  terminate  by  arbor- 
ization about  these  cells.  In  spite  of  the  rather  accurate 
knowledge  we  have  of  the  structures  in  the  canal  of  the 
cochlea,  we  are  not  able  to  determine  which  of  these  is 
directly  responsible  for  the  excitation  of  the  nerve-endings. 
It  is  plain  that  vibrations  set  up  in  the  fluid  of  the  vestibule 


Tectorial 
membrane 


Inner 
hair-cells 


ner  rod      Outer  rod        Basilar  membrane 


FIG.  51. — The  organ  of  Corti. 
(From  Ladd  and  Woodworth,  after  Retzius.) 


would,  in  passing  up  the  scala  vestibuli  be  communicated 
through  the  membrane  of  Reissner  to  the  fluid  in  the  scala 
media  and  set  up  vibrations  of  the  basilar  membrane  and 
the  hair-cells  which  rest  upon  it.  What  is  needed,  however, 
to  explain  the  physiological  basis  of  hearingja-^ome  appa- 
ratus which  will  act  not  as  a  whole  but  will  respond  in  parts, 
differ  enT^ocies  to~clifferent  kinds  ol^vibrationG.i  The 

~ 


or 


many  different  tohaT  qualities^  wtiich~the  ear  can  detect  call 
for  a  high  degree  of  differentiation  in  the  end-organs,  in 
er  that  different  nerve  -  impulses,  corresponding  to  the 
erent  sensory  qualities  in  consciousness,  may  be  sent  to 
brain.  The  '  '  sympathetic-resonance  theory  '  '  of  Helm- 
holtz  has  been  very  widely  held.  He  first  suggested  that 
the  rods  of  Corti  were  responsible  for  our  tonal  discrimina- 
tion, but  he  abandoned  this  theory  because  it  was  demon- 


AUDITORY    SENSATIONS  1  51 

strated  that  in  birds  the  rods  of  Corti  were  lacking.  Fur- 
ther, they  were  not  numerous  enough  to  account  for  the 
number  of  tonal  qualities;  and  in  addition  they  do  not  differ 
sufficiently  in  size  and  structure.  He  then  accepted  the  sug- 
gestion of  Hensen  that  the  fibres  of  the  basilar  membrane, 
which  differ  in  length,  were  capable  of  vibrating  sympatheti- 
cally  with  the  different  vibrations  of  the  fluid  of  the  ear. 
He  found,  therefore,  in  the  basilar  membrane  a  harp  with 
its  different  strings  tuned  for  different  vibrations.  The 
physics  of  this  theory  may  be  demonstrated  very  simply  by 
lifting  the  dampers  from  the  strings  of  a  piano  and  singing  a 
tone  into  them;  the  vibration  of  the  voice  will  set  in  vibra- 
tion sympathetically  only  that  string  which  is  tuned  to  the 
tone  sung.  So,  thought  Helmholtz,  the  different  fibres  vi- 
brate sympathetically  and  selectively  to  the  vibrations  con- 
veyed to  it  by  the  mechanism  of  the  ear.  There  are  some 
objections  to  the  theory  on  the  ground  that  the  fibres  cf 
the  basilar  membrane  are  so  extremely  short  and  vary  in 
length  so  slightly  that  they  could  not  be  thought  of  as  reso- 
nators, or  "vibrating  strings."  Moreover,  if  they  do  vibrate, 
the  range  of  vibration  would  be  too  limited  to  account  for 
the  wide  range  of  tonal  differences.  Recently  Hardesty1  has 
discovered  that  the  fibres  of  the  basilar  membrane  are  bound 
together  by  cross-fibres  in  such  a  way  that  it  seems  improb- 
able that  they  could  vibrate  individually. 

Many  other  theories  of  audition  have  been  proposed. 
The  most  noteworthy  is  the  "  telephone  theory."2  This 
theory  holds  that  every  rate  of  vibration  sets  up  vibrations 
in  the  organ  of  Corti  as  a  whole,  affecting  the  adjacent  hair- 
cells.  The  rate  of  vibration  is  transmitted  to  the  nerve-cells 
and  through  them  telephoned  to  the  brain,  where  they  are 
interpreted  in  terms  of  tonal  sensations.  According  to  this 
theory,  the  analysis  of  the  stimulus  takes  place  in  the  brain- 
cells,  rather  than  in  the  end-organs,  as  is  assumed  in  the 
Helmholtz  theory. 

1  American  Journal  of  Anatomy,  1908,  VIII,  p.  109. 

2  Rutherford:  "The  Sense  of  Hearing,"  Lancet,  1887,  1,  pp.  2-6. 


/L. 


152  PSYCHOLOGY 

Brain  Centres. — The  cortical  centre  for  hearing  is  in  the 
superior  convolutions  of  the  temporal  lobes.1  Complete 
deafness  follows  the  destruction  of  both  temporal  lobes.  In 
cases  of  lesion  in  one  temporal  lobe,  partial  deafness  in  the 
opposite  ear  follows.  Sometimes  when  the  lesion  is  not  ex- 
tensive or  is  located  in  neighboring  areas,  there  is  merely 
a  disturbance  of  hearing,  or  a  loss,  not  of  the  sensations  of 

/  hearing,  but  of  their  associations,  as  in  "word-deafness"  (in- 

I  ability  to  understand  spoken  words) .  In  this  case  the  sounds 
are  heard,  but  their  meanings  have  been  lost.  In  right- 
handed  persons  this  occurs  when  the  lesion  is  located  in  the 
left  lobe.  Since  complete  destruction  of  the  auditory  centre 
on  one  side  does  not  cause  complete  deafness  in  the  opposite 
ear,  it  would  appear  that  not  all  of  the  fibres  from  one  ear 
cross  to  the  opposite  side  of  the  brain,  but  rather  that  each 
ear  sends  fibres  to  both  sides  of  the  brain.  The  path  of  the 
auditory  impulses  is  roughly  from  the  ear  to  the  nuclei  in 
the  upper  part  of  the  medulla;  from  there  by  a  second  set  of 
neurones  they  cross  over  to  the  opposite  side  of  the  medulla, 

t  thence  by  a  third  set  of  neurones  to  the  internal  geniculate 
^  and  inferior  quadrigeminum  of  the  mid-brain,  and  from 
^  there  by  a  fourth  set  of  neurones  to  the  temporal  lobe.  The 

;  pathways  by  which  the  two  branches  of  the  auditory  nerve 
(the  vestibular  and  cochlear)  reach  the  brain  are  as  distinct 
as  their  distribution  in  the  ear,  which  is,  of  course,  evidence 
for  the  difference  in  function  of  the  two  parts  of  the  inner 
ear.  The  fibres  of  the  vestibular  branch  pass  from  the  semi- 
circular canals  to  a  nucleus  (near  the  nuclei  for  the  cochlear 
fibres)  in  the  medulla,  from  there  a  second  set  of  fibres  crosses 
over  to  the  opposite  side  of  the  medulla  and  go  to  the  cere- 
bellum. 

The  Stimulus. — Air-waves  set  up  by  vibrating  bodies  are 
the  normal  stimuli  for  auditory  sensations.  These  air-waves 
may  vary  in  length,  in  amplitude,  and  in  form.  The  shorter 
the  wave  the  quicker  the  rate  of  vibration.  For  instance, 

1  See  Figure  28. 


AUDITORY   SENSATIONS 


153 


(a)  Simple  Harmonic  Wave 


(b)  Simple  Harmonic  Wave 


the  short  wires  of  the  piano  give  a  short  wave-length  and  a 
very  rapid  rate  of  vibration  per  second,  c3's  vibration  rate  is 
1,024  vibrations  per  second.  On  the  other  hand,  the  long 
wires  give  a  longer  wave- 
length and  a  slower  rate  of 
vibration  per  second;  C0's 
vibration  rate  is  64  vibra- 
tions per  second.  The 
length  of  the  air-wave  (or 
the  rate  of  vibration)  de- 
termines the  pitch  of  the 
sound.  Variations  in  the 
amplitude  of  a  given  wave- 
length correspond  to  the 
variations  in  the  intensity, 
or  loudness,  of  the  result- 
ing sound.  The  form  of 
the  air-wave  determines 
whether  the  resulting 
sound-sensation  is  simple 
or  compound.  The  peri- 
odic simple  harmonic 
waves  give  simple  tones, 
while  the  periodic  com- 
pound harmonic  waves 
give  compound  or  compos- 
ite tones,  or  clangs,  as  they 
have  sometimes  been 
called. 

Most  vibrating  bodies 

give  out  compound  waves.  This  is  due  to  the  fact  that 
they  are  capable  of  vibrating  not  only  as  wholes,  but  also 
in  parts.  A  string,  for  instance,  vibrates  not  only  in  its 
entire  length,  but  also  in  halves,  thirds,  fourths,  etc.,  each 
part  vibrating  at  the  same  time,  but  at  different  rates. 
The  halves  execute  twice  as  many  vibrations  as  the  whole 


(c)  Compound  Harmonic 
Resultant  of  (a)  and  (6). 


FIG.  52. — Both  (a)  and  (&)  represent 
simple  harmonic  waves  of  different 
lengths;  (b)  is  one-half  the  wave- 
length of  (a),  but  its  rate  of  vibration 
is  twice  that  of  (a).  These  waves, 
when  acting  separately,  produce  sim- 
ple tones  which  differ  in  pitch.  When 
they  act  together  the  resultant  wave 
is  represented  by  (c)  a  compound 
harmonic  wave,  producing  a  compound 
tone,  composed  of  the  two  tones  cor- 
responding to  waves  (a)  and  (b). 


1 54  PSYCHOLOGY 

string,  the  thirds  three  times,  and  the  fourths  four  times  as 
many.  All  these  vibrations  produce  a  resultant  air-wave  of 
the  compound  type,  which  form  of  stimulus  arouses  a  com- 
pound tone.  A  compound  wave  may  therefore  be  treated 
as  a  composite  of  simple  waves,  and  the  resulting  compound 
tone  as  a  complex  of  pure  tones.  Periodic  waves  (simple  or 
compound)  jye_j>o  termed  because  they  repeat  the  same 
movements,  while  non-periodic  are  irregular. 

The  normal  manner  Tor  sound-vibrations  to  reach  the 
inner  ear  is  through  the  external  ear,  tympanic  membrane 
and  ossicles  of  the  middle  ear  to  the  fluid  of  the  vestibule. 
But  we  have  already  mentioned  the  fact  that  sound-stimuli 
may  reach  the  inner  ear  by  conduction  through  the  bones  of 
the  skull.  It  is  practically  impossible  to  excite  the  end- 
organs  of  one  ear  without  at  the  same  time  affecting  those 
in  the  other  ear;  for  even  if  one  ear  is  completely  stopped, 
the  stimulus  may  be  conducted  to  it  through  the  skull-bones 
or  through  the  Eustachian  tubes. 

Noises. — -The  difference  m  the  mental  qualities  of  noises 
and  tones  seems  to  be  so  great  that  it  has  been  suggested 
that  they  must  arise  from  different  end-organs.  Accordingly, 
attempts  have  been  made  to  find  other  structures  than  those 
in  the  cochlea  to  which  noise  could  be  attributed.  The  sac- 
cule  of  the  vestibule  was  supposed  to  be  that  structure.  If, 
however,  noises  and  tones  have  their  origin  in  different  end- 
organs,  it  is  very  probable  that  there. would  be  pathological 
cases  reported  in  which  ability  to  hear  noises  would  exist 
together  with  tonal  deafness,  or  that  noises  would  be  lost  and 
tones  retained.  But  no  such  cases  have  been  reported. 
Careful  observation  reveals  a  closer  relationship  between 
noises  and  tones  than  might  be  supposed.  Certain  noises 
reveal  tonal  qualities.  The  hum  of  street  noises,  the  drone 
of  the  waves,  the  buzz  of  many  voices,  or  even  the  pop  of 
a  pistol  possess  slight  tonal  qualities.  On  the  other  hand, 
many  closely  related  tones,  if  sounded  at  the  same  time, 
produce  a  noise.  Strike  a  dozen  or  more  adjacent  keys  of 


AUDITORY   SENSATIONS  155 

the  piano  simultaneously  and  note  the  effect.  A  single  in- 
stantaneous exposure  of  a  vibrating  tuning-fork  may  be  heard 
not  as  a  tone  but,  if  the  exposure  is  short  enough,  as  a  noise. 

Noises  may  be  divided  into  two  classes:  (i)  the  momentary 
or  explosive  noises,  and  (2)  the  continuous  noises.  Of  the 
first  class  we  have  such  noises  as  are  represented  by  the 
words  "crackle,"  "crack,"  "snap,"  "pop."  Of  the  second 
class  we  have  the  hissing,  roaring,  rumbling  sounds.1  No 
success  has  met  the  efforts  to  further  analyze  these  complex 
noise  experiences  into  their  elementary  sensory  qualities. 
How  many  simple  noise  qualities  there  are  has  not  been 
determined. 

If  we  accept  the  Helmholtz  theory  that  simple  tones  are 
the  result  of  the  vibration  of  single  fibres  in  the  basilar  mem- 
brane, we  might  further  assume  that  noise  arises  when  a 
large  number  of  adjacent  basilar  fibres  are  set  simultaneously  | 
vibrating,  i.  e.,  while  simple  tones  come  from  the  stimulation 
of  single  fibres  (or  a  series  of  properly  related  fibres),  noises'  . 
result  from  the  stimulation  of  the  basilar  membrane  as  a) 
whole,  or  in  large  sections  or  blocks. 

Tones.  —  Tones  constitute  a  continuous  series  of  con- 
stantly changing  sensory  qualities  from  the  lowest  notice- 
able pitch  to  the  highest.  The  change  in  pitch  corresponds  . 
to  the  change  in  the  vibration  rate  gf  foe  stimulus.  The  f" 
lowest  tone  that  can  be  heard  varies  somewhat  in  different 
individuals,  but  lies  between  20  and  28  vibrations  per  second, 
while  the  highest  tone  corresponds  to  vibration  rates  of  from 
22,000  to  43,000  vibrations.  Some  investigators  report  in- 
dividuals who  can  detect  tones  from  vibration  rates  as  high 
as—  j&ooo.  The  average,  however,  is  about  32,000  vibra- 
tions. The  extreme  limits  of  tonal  hearing  may  safely  be 
put  at  1  6  vibrations  for  the  lowest  tone  and 


tions  for  \rfe  highest  tone.2     In  old  age,  the  end-organs  for 

kitchener:  "Text-Book  of  Psychology,"  p.  95. 

z  The  upper  limit  of  tonal  hearing  may  be  determined  by  the  Gallon  whistle, 
an  instrument  found  in  any  psychological  laboratory.  The  lower  limit  is 
determined  by  means  of  large  tuning-forks. 


156  PSYCHOLOGY 

tone  become  less  responsive,  restricting  the  range  of  tonal 
qualities  both  at  the  higher  and  lower  limits.  Between  the 
highest  and  lowest  tone,  there  are  for  the  human  ear  over 
11,000  discriminable  tones.  The  ordinary  musical  scale, 
i  however,  makes  use  of  only  about  100  tones  lying  at  the 
lower  part  of  the  series;  88  of  these  tones  and  half-tones  are 
represented  on  the  keyboard  of  the  grand  piano,  from  AZ — 
26.6,  to  q5 — 4,096  vibrations. 

The  ability  to  detect  differences  in  pitch  is  not  the  same 
for  all  parts  of  the  scale,  but  in  its  middle  part — from  c1  to  c* 
(256  to  512  vibrations) — the  average.,  unpractised  ear  can 
sense  a  difference  in  pitch  corresponding  to  a  difference  in 
.1  the  stimulus  from  8  to  16  vibrations.     This  may  be  reduced 
II  tty_j>iactice.     Trained  musicians  have  detected  a  difference 
j\  of  one-third  of  a  vibration.     Some  individuals  are  extremely 
insensitive  to  differences  of  pitch.     Cases  have  been  reported 
where  a  difference  of  64  vibrations  (two  whole  tones  on  the 
musical  scale)  cannot  be  distinguished.     The  ability  to  dis- 
tinguish differences  in  tones  must  not  be  confused  with  the 
ability  to  "sing  in  tune."     A  singer  who  is  able  to  detect  a 
difference  of  one-half  vibration  may  not  be  able  to  control 
the  pitch  of  his  voice  within  the  limits  of  8  vibrations  or  a 
quarter  of  a  tone. 

When  different  notes  are  struck  on  a  musical  instrument, 
we  usually  determine  the  pitch  of  each  note  relatively,  by 
referring  the  given  tone  to  a  standard  tone  whose  place  in 
the  scale  we  already  know.  Given  this  standard,  we  can 
name  any  other  tone  by  reference  to  the  standard.  There 
are  some  few  individuals,  however,  who  seem  to  possess 
what  is  known  as  "absolute  pitch."  They  are  able  to  judge 
dbsohde  tone,  which  is  quite  different  from  determining  dif- 
ferences in  the  pitch  of  two  tones  or  in  judging  the  interval 
between  them.  In  absolute  pitch  there  must  be  a  very 
close  and  definite  association  between  the  tonal  quality  and 
the  name  of  the  tone,  which  is  not  present  in  the  majority 
of  musicians. 


AUDITORY   SENSATIONS  157 

A  certain  form  of  tone-deafness  may  produce  what  are 
known  as  tonal  gaps  and  tonal  islands.  These  cases  may 
appear  when  the  outer  and  middle  ears  are  perfectly  normal, 
thus  indicating  the  absence  of  certain  specialized  end-organs 
for  tone.  It  may  happen  that  although  the  range  of  tonal 
qualities  is  as  great  as  usual,  certain  groups  of  tones  cannot 
be  heard,  making  a  gap  in  the  otherwise  normal  tonal  series, 
Or,  in  other  cases,  only  a  few  of  the  tones  may  be  heard,  t 
while  those  above  and  below  this  group  are  absent,  making 
a  "tonal  island."  Such  phenomena  furnish  further  evidence 
of  distinct  end-organs  for  different  tones. 

Compound  Tones. — Only  a  few  specially  constructed  in- 
struments are  capable  of  producing  simple  tones,  or  at  least 
tones  that  approximate  simple  tones.  The  tuning-fork  is 
one  of  these.  It  produces  a  simple  pendular  wave  and  con- 
sequently a  simple  tone.  Nearly  all  resounding  bodies,  even 
the  vocal  cords,  give  non-pendular  or  complex  waves  and 
arouse  complex  tones.  When  a  single  note  is  sounded  by 
the  voice,  piano,  violin,  etc.,  what  appears  to  the  untrained 
ear  as  a  single  tone  can,  by  careful  observation,  be  analyzed 
into  several  simple  tones,  called  partial  tones,  sounding  simul- 
taneously. The  lowest  partial — the  most  dominant  or  in- 
tense tone — is  the  fundamental  tone,  and  the  others  are  the 
upper  partials,  sometimes  called  overtones.  These  upper  par- 
tials  are  caused  by  the  fact,  already  mentioned  in  the  dis- 
cussion of  sound-stimuli,  that  resonant  bodies  vibrate  in 
parts  as  well  as  in  wholes.  The  fundamental  arises  from 
the  vibration  of  the  whole  body,  while  the  upper  jpartials 
arise  from  the  vibrations  of  its  respective  parts.  If,  for  in- 
stance, the  wire  of  a  "sonometer"  (a  Jong  wire  stretched  on 
a  resounding  box)  is  struck  with  the  sound  hammer,  it  will 
vibrate  as  a  whole,  in  halves,  in  thirds,  in  fourths,  etc.  Each 
part  will  give  out  its  own  simple  tone,  so  that  the  tone  that 
is  heard  is  compound,  made  up  of  the  fundamental  tone 
(from  the  whole  wire),  the  second  partial  (from  the  half 
wire),  the  third  partial  (from  the  third  of  the  wire),  the  fourth 


158  PSYCHOLOGY 

partial  (from  the  fourth  of  the  wire).  Other  partials  may 
be  present,  but  they  are  very  faint.  The  intensity  of  the 
partials  wanes  as  the  parts  of  the  wire  from  which  they  arise 
become  shorter.  However,  these  four  simple  tones,  the  fun- 
damental and  the  three  other  partials  mentioned,  can  be 
easily  analyzed  out  of  the  compound  tone.1  The  untrained 
ear  may  have  some  difficulty  at  first  in  hearing  all  the  par- 
tials mentioned,  but  a  little  practice  will  enable  one  to  de- 
tect them.  It  should  be  noticed  that  the  upper  partials  or 
overtones  are  always  higher  than  the  fundamental,  and  that 
they  correspond  to  vibration  rates  which  are  simple  multi- 
ples of  the  vibration  rate  of  the  fundamental.  Thus,  if  the 
whole  wire  has  a  rate  of  256  vibrations,  the  second  partial  is 
512  vs.,  twice  the  rate  of  the  fundamental;  the  third  partial 
is  768  vs.,  three  times  the  fundamental;  the  fourth  partial  is 
1,024  vs.,  four  times  the  fundamental. 

Timbre. — The  character  of  compound  tones,  which  is 
known  as  timbre,  is  due  to  the  presence  in  them  of  the  partial 
tones  or  overtones  which  we  have  just  discussed.  It  is  evi- 
dent that  a  given  tone  of  the  same  pitch  and  intensity  sounds 
differently  on  different  musical  instruments.  We  can  easily 
tell  the  difference  between  the  same  note  on  a  piano  and  on  a 
violin.  This  difference  is  due  to  the  difference  in  timbre, 
and  timbre  is  determined  by  the  number  and  the  intensity 
of  the  overtones  present  in  the  tones.  The  tones  of  different 
instruments  vary  in  this  respect.  The  flute  has  few  and 
weak  overtones.  This  gives  its  tone  a  dull  character.  In 
brass  instruments  the  higher  overtones  predominate,  giving 
a  piercing  quality  to  their  tones.  And  so  we  find  great  variety 
in  the  character  of  the  overtones  in  various  musical  instru- 
ments. Some  may  have  the  odd-numbered  overtones  and 


1  A  simple  way  to  isolate  the  partial  tones  is  as  follows:  To  isolate  the 
second  partial,  strike  the  wire  at  one-fourth  its  distance  from  one  end  to  the 
other,  then  damp  exactly  in  the  middle  by  touching  lightly  with  a  piece  of 
cotton;  third  partial,  strike  at  one-sixth  and  damp  at  one- third;  fourth  partial, 
strike  at  one-eighth  and  damp  at  one-fourth. 


AUDITORY    SENSATIONS  159 

some  may  have  the  even-numbered  overtones;  some  may 
possess  intense  lower,  others  intense  higher  overtones.  Of 
course,  the  noises  which  accompany  the  production  of  tones, 
like  the  plucking  sound  of  the  banjo  or  the  scraping  of  the 
violin,  may  also  aid  one  in  detecting  the  difference  in  tones 
of  different  instruments,  and  have  been  considered  by  some 
authorities  as  contributing  to  differences  in  timbre. 

Beats. — -If  two  cl  tuning  forks,  each  of  256  vs.,  are  set 
vibrating  at  the  same  time,  the  two  tones  will  fuse  together, 
giving  a  perfectly  smooth,  uniform  tone.  If,  now,  one  of 
the  forks  is  weighted  with  a  bit  of  plastic  clay  or  chewing- 
gum,  its  vibration  frequency  will  be  lessened  and,  conse- 
quently, its  pitch  slightly  lowered.  The  two  forks  will,  how- 
ever, give  a  single  tone,  but  the  intensity  of  the  tone  will 
rise  and  fall  regularly.  The  points  where  the  tone  wanes  in 
intensity  are  called  beats.  They  are  due  to  the  interference 
of  the  sound-waves  of  the  two  tones.  The  waves  of  the 
slower  fork  lag  behind  the  waves  of  the  other  fork  more 
and  more  until  a  point  is  reached  where  the  crest  of  the  one 
and  the  trough  of  the  other  coincide.  The  waves  then  jn-  ; 
terfere  or  oppose  each  other  and  momentarily  diminish  the  ' 
intensity  of  the  combined^oneT  It  is  plain  that  the  number 
of  beats  in  a  second  will  oe  equal  to  the  difference  between 
the  vibration  frequencies  of  the  two  forks.  If  the  weighted 
fork  is  reduced  to  255  vs.,  while  the  other  remains  at  256, 
there  will  be  exactly  one  beat  per  second.  By  gradually 
increasing  the  weight  upon  the  fork,  the  number  of  beats 
per  second  will  be  increased.  As  the  beats  become  more 
rapid,  the  character  of  the  tone  changes.  With  2  or  3 
beats  a  second  the  tone  rises  and  falls  gradually,  at  8  per 
second  the  beats  begin  to  strike  more  vigorously,  while  further 
increase  up  to  16  gives  a  rattling  character  to  the  tone.  At 
28  per  second  the  tone  is  rough,  harsh,  and  discordant;  the 
maximum  ^dissonance  between  the  tones  is  reached  at  about 
this  point.  When  the  number  of  beats  reach  about  50  per 
second  for  this  part  of  the  scale,  the  dissonance  disappears  and 


l6o  PSYCHOLOGY 

the  two  tones  flow  together  smoothly  again  and  manifest  no 
disturbance. 

Careful  observation  shows  that  when  the  pitch  of  the 
lower  tone  becomes  sufficiently  different  (about  8  vs.)  from 
the  other  tone  to  be  distinguished  from  it,  an  "intertone" 
appears,  lying  midway  between  the  two  generating  tones. 
It  is  this  tone  which  carries  the  beat.  When  the  interval 
between  the  two  generating  tones  reaches  40  vibrations,  the 
intertone  becomes  inaudible  and  the  two  generating  tones 
emerge  and  become  distinguishable. 

Beats  may  be  heard  even  when  the  tones  are  completely 

separated    and    conducted    separately    through    sound-tight 

;  tubes,  one  to  each  ear.     Since  the  sound-waves  in  this  case 

5  are  led  to  different  end-organs,  it  was  supposed  by  some 

that  beats  are  of  central  origin,  i.  e.,  that  they  are  produced 

/)     in  the  cortical  centres  and  not  in  the  end-organs.     But  this 
o/v   »y* 
«A  V^  theory  is  discredited  by  the  fact  that  sound-waves  in  each 

+  \}^ar  can  Pass  by  bone  conduction  to  the  opposite  ear.  On 
account  of  this  it  is  not  possible  to  separate  the  two  tones 
so  far  as  the  ears  are  concerned. 

Combination  Tones. — If  two  tones  that  are  not  too  similar 
in  pitch  are  sounded  together,  there  may  be  heard  a  third 
tone,  much  lower,  sounding  with  them;  and  if  the  observa- 
tion is  keen  enough,  a  faint  fourth  tone  may  be  heard,  much 
higher  than  the  two  original  tones.  The  lower  extra  tone 
is  called  a  difference  tone,  and  the  higher  extra  tone  a  summa- 
tion tone.  Both  are  known  as  combination  tones.  The  differ- 
ence tone  has  a  vibration  rate  equal  to  the  difference  in  rate 
between  the  original  tones,  and  the  summation  tone  has  a 
rate  equal  to  the  sum  of  the  rates  of  the  two  original  tones. 
If,  for  instance,  we  sound  the  tones  d4  (2,304  vs.)  and  g3 
(1,536  vs.),  the  difference  tone  will  be  g2  (768  vs.),  and  the 
summation  tone  will  be  b4  (3,840  vs.).*  The  summation  tone 

*The  higher  tones  are  preferable  for  demonstrating  combination  tones. 
Quincke's  tubes  d4  and  g3,  when  sounded  together,  bring  out  these  tones  fairly 
well. 


AUDITORY   SENSATIONS  l6l 

is  very  weak.  Besides  the  difference  tone  mentioned,  a  sec- 
ond, third,  and  even  a  fourth  difference  tone  has  been  de- 
tected. The  cause  of  these  combination  tones  is  supposed 
to  originate  in  the  ear  itself — either  in  the  tympanic  mem-// 
brane  or  in  the  membrane  covering  the  round  window.  It 
has  been  demonstrated  that  when  thin  membranes  are  acted 
upon  simultaneously  by  two  sound-waves  whose  frequencies 
hold  a  certain  relation  to  each  other,  other  waves  are  prop- 
agated by  the  membranes.  It  seems  necessary  to  explain 
combination  tones  in  this  way,  for  they  have  been  demon- 
strated when  no  external  air-vibrations  corresponding  to 
them  were  present.  For  this  reason  they  have  been  called 
head-tones,  because  the  vibrations  causing  them  are  generated 
withirrthe  head. 

Intensity. — The  intensity  of  a  sound-stimulus  depends 
upon  |he  amplitude  p,f  \\\*  rmiiiifil  Tn: — ,  i~H  trr '  •nt"-r:<y 
of  the  sensation  increases  with  the  intensity  of  the  stimulus. 
The  relation  between  the  intensity  of  the  stimulus  and  the 
intensity  of  the  sensation  was  discussed  under  Weber's  Law 
(seepage  101).  Before  a  sound-stimulus  can  arouse  a  sensa- 
tion it  must  reach  a  certain  degree  of  energy.  In  order  to 
determine  accurately  the  minimal  or  just-observable  sound- 
stimulus,  tests  must  be  made  in  a  sound-proof  room,  in  order 
to  eliminate  all  distracting  sounds.  There  are,  however, 
some  individuals  who  can  hear  more  distinctly  when  they 
are  surrounded  by  a  medley  of  sounds,  such  as  the  sounds  of 
a  noisy  street,  or  shop,  or  in  a  room  where  a  buzz  of  conver- 
sation is  going  On.  SJnrh  individuals  pOSSCSS  a  bluptpH  gpngi- 

tivity  to  sound.  It  requires  rather  intense  sound-stimuli  to 
overcome  the  inertia  of  a  sluggish  auditory  apparatus  (in 
some  cases,  the  ossicles  of  the  middle  ear).  After  the  appa- 
ratus is  once  limbered  up,  it  becomes  more  sensitive  to  sound- 
stimuli. 

Extensity. — In  the  case  of  cutaneous  sensations,  one  and 
the  same  stimulus  may  act  upon  like  end-organs,  situated  at 
different  points  on  the  skin.  In  this  case  it  arouses  the  same 


1 62  PSYCHOLOGY 

quality  of  sensation,  which,  however,  may  vary  in  space 
character.  In  hearing,  however,  this  is  probably  not  true. 
Here  a  single  stimulus  acts  only  upon  a  single  auditory  fibre, 
pr  the  same  band  of  fibres  (Helmholtz  theory).  If  this  is 
true,  a  given  tone-sensation  cannot  vary  in  extensity.  The 
extensity  of  a  given  tone  and  its  quality  would  never,  for 
this  reason,  be  separated  in  sensory  experience.  Tones  do 
not,  therefore,  possess  spatial  arrangement  or  "  alongsideness  " 
among  themselves.  But  they  may  possess  extensity  in  the 
sense  that  we  have  used  the  word  on  a  preceding  page.  The 
low  bass  tones  seem  bigger — more  massive — than  the  high 
tones  of  the  treble.  It  has  been  suggested  that  the  differ- 
ences in  pitch  are  in  themselves  differences  in  extensity. 
This  would  apparently  call  for  another  theory  for  the  physio- 
logical basis  of  hearing.  In  such  a  theory  high  tones  would 
correspond  to  the  stimulation  of  only  a  few  cells  or  fibres, 
while  the  low  or  more  massive  tones  would  correspond  to  the 
stimulation  of  a  larger  number. 

Musical  Tones,  Consonance,  and  Dissonance. — If  we  com- 
pare the  different  tones  in  any  tonal  series,  we  shall  find  that 
those  that  are  at  certain  intervals  apart  are  psychologically 
more  alike  than  others,  i.  e.,  that  some  pairs  of  tones  fuse  or 
blend  much  more  completely  than  do  other  pairs.  On  the 
other  hand,  some  tones  stand  alone  and  refuse  to  unite. 
The  selection  of  tones  for  aesthetic  purposes  (music)  was 
determined  by  this  likeness  and  difference  in  the  sensory 
character  of  tones.  The  musical  scale  is  based  primarily 
upon  the  fact  that  any  tone  whose  vibration  rate  is  double 
that  of  another  will  fuse  readily  with  it,  producing  the  maxi- 
mum degree  of  consonance,  or  union.  This  determines  the 
octave.  The  keyboard  of  the  grand  piano  has  seven  and  a 
fraction  octaves,  ranging  from  A2  (26%  vs.)  to  c5  (4,096  vs.).1 

1Th2se  are  the  vibration  frequencies  adopted  for  scientific  purposes.  The 
German  scale  would  read  A2,  equals  27^  vs.  to  c5,  equals  4,224  vs.  In  this 
scale,  middle  c  (c1)  equals  264  vs.  On  the  English  piano,  middle  c  is  270  vs. 
While  the  absolute  vibration  frequencies  may  differ"  on  different  scales,  the 
tonal  intervals  or  tonal  relations  are  always  the  same. 


AUDITORY   SENSATIONS  163 

The  octaves  are  as  follows: 
Subcontra  octave  ..........  C2  =        16  vs.  to  Ci  =       32  vs. 


Contra 

Great 

Small 

Once  accented 

Twice 

Thrice         " 

Four  times  " 


.  Ci  =       32  vs.  to  C0  =       64  vs. 

.C0  =       64  vs.  to  c°  =      128  vs. 

.  c°  =      128  vs.  to  c1  =      256  vs. 

.  c1  =      256  vs.  to  c2  =      512  vs. 

.  c2  =     512  vs.  to  c3  =  1,024  vs. 

.  c3  =  1,024  vs.  to  c4  =  2,048  vs. 

.  c4  =  2,048  vs.  to  c5  =  4,096  vs. 


To  illustrate  the  tonal  intervals  within  the  octave,  we 
may  select  the  once-accented  octave  c1  (middle  c)-c2.  The 
whole  tones  (diatonic  scale)  within  the  octave  are: 

Ic1  =  256  vs. ,  ? .  c. 
d1  =  288  vs.  |t 

£  -3*ovsr  ^ 
f1  =  341.3  vs.  , 
g1  =384 vs.-  »; 

a1  =  426.6  vs.       '.  cf 
b1  =  480  vs.'    *M  jt 
c2  =  512  vs. 

The  intervals  separating  the  successive  notes  of  this  scale 
may  be  expressed  by  the  ratio  of  their  vibration  frequencies. 
The  interval  of  c1  and  d1  =  8  r.  9;  d1  and  e1  =  9  : 10;  e1  and  f1  = 
15  :  16;  f1  and  g1  =  8  :  9;  g1  and  a1  =  9  : 10;  a1  and  b1  =  8  19; 
b1  and  c2  =  15  :  16.  The  interval  of  c1  and  g1  =  2  : 3  (c1  = 
256  vs.,  g1  =  384  vs.;  256  :  384  =  2:3).  As  has  been  said, 
the  most  perfect  consonance  of  all  the  possible  intervals  is 
that  of  c1  and  c2  =  1:2.  Within  the  octave,  other  intervals 
may  be  selected,  giving  decreasing  degrees  of  consonance, 
some  intervals  producing  a  decided  dissonance.  If  we  ar- 
range the  intervals  in  their  order  of  consonance  or  tonal  like- 
ness, starting  with  c1,  we  have: 

c1  and  c'2  =1:2  (octave). 
c1  and  g1  =2:3  (fifth). 
c1  and  f1    =3:4  (fourth). 
c1  and  e1   =4:5  (major  third). 
c1  and  a1  =3:5  (major  sixth). 


164  PSYCHOLOGY 

These  are  the  pleasing  or  consonant  intervals  within  the 
octave.  On  the  other  hand,  the  interval  of  c1  and  d1  =  8:9, 
major  second;  and  c1  and  b1  =  8  : 15,  major  seventh,  are  de- 
cidedly dissonant  and  displeasing.  In  the  simple  diatonic 
scale  any  two  tones  whose  vibration  frequencies  stand  to  each 
other  as  i  :  2  Joctave) ,  2  :_g  jfifth),  3  14  (fourth),  4. :  5  (major 
third),  or  3  :  5  (major  sixth)  will,  when  sounded  together, 
blend  without  roughness  or  dissonance.  If,  however,  we 
should  start  with  any  other  tone  (tonic),  say  d1,  and  calcu- 
late the  vibration  frequencies  of  the  tones  that  lie  a  fifth,  a 
fourth,  a  major  third,  a  major  sixth,  etc.,  above  d1,  there 
would  not  be  a  sufficient  number  of  tones  in  the  diatonic 
scale  to  construct  these  intervals.  So  it  was  necessary,  in 
order  to  maintain  these  relations  between  the  tones,  to  insert 
other  tones  within  the  octave.  But  such  a  large  number  of 
new  tones  is  required  to  make  the  intervals  exact  that  it 
makes  the  octave  unwieldy.  In  overcoming  this  difficulty,  a 
compromise  was  made  by  inserting  fjyp  half-tones  for  the 
pianoforte  and  other  similarly  tuned  instruments,  so  that 
the  octave  contains  twelve  tones,  equally  distant  from  each 
other.  This  is  the  equally  tempered  jtcale,  which  is  now  in  use 
in  this  country  and  Europe.  The  only  exactly  tuned  interval 
in  the  equally  tempered  scale  is  the  octave;  all  the  others  are 
slightly  out  of  tune.  The  approximation  to  the  true  intervals 
is  so  close,  however,  that  for  all  but  the  most  sensitive  and 
highly  trained  ears  the  result  is  satisfactory. 

Consonance  and  dissonance  have  been  explained  in  several 
ways.  According  to  Stumpf,1  consonance  is  due  to  the  fusion 
of  tones.  Those  tones  that  blend  smoothly  and  fuse  with 
one  another  more  or  less  completely,  so  that  the  resulting 
sensory  experience  resembles  a  single  tone  sensation,  are  con- 
sonant; while  those  tones  that  refuse  to  blend  or  fuse  together 
into  a  single  experience  and  remain  apart,  are  dissonant. 
Unity  of  tonal  impression  is,  therefore,  according  to  Stumpf, 

1  "Konsonanz  und  Dissonanz,"  Beitrage  zur  Akustik  und,  Musikwisstnschaft, 
1898,  I,  i. 


AUDITORY   SENSATIONS  165 

the  measure  of  consonance.  Helmholtz  considers  consonance 
the  absence,  and  dissonance  the  presence  of  beats  in  simul- 
taneously  sounding  tones.  In  considering  this  theory,  we 
must  remember  that  most  single  tones  are  compounds,  made 
up  of  fundamentals  and  overtones.  The  overtones  of  one 
noternay  cc-incid|£  Q  r 


The  degree  of  consonance  of  tones  goes  hand  in  hand 
with  the  amount  pi  coincidence  of  their  overtones.     In  the 
octave,  where  there  is  perfect  consonance,  ffie  overtones  co- 
incide and,  therefore,  there  is  no  beating.     In  the  minor  sixth  . 
(c  —  /a  =  5j^,  just  on  the  border-line  between  consonance  1 
and  dissonance,  the  lower  overtones  (the  second  of  c  and  the 
first  of  !*a)  beat  audibly  with  each  other.     In  more  dissonant 
intervals  the  overtones  beat  still  more  markedly.     The  rough-  1 
ness  of  dissonant  intervals,  produced  by  the  beats,  is  unpleas-/ 
ant,  just  as  intermittent  sensations  of  any  kind  are  unpleasant.  \ 
In  regard  to  successive  tones,  Helmholtz  has  suggested 
that  their  relation  depends  upon  the  similarity  or  dissimilarity 
of  their  overtones.     \  tinne-^iJiBfiStJfifefiJ^_W^Y^  tone  be- 
cause the  over^nnps  of  frfoe.  t^yfl  ftjre  coincident.     In  passing 
from  the  one  to  the  other  a  large  part  of  the  end-organs 
active  for  the  first  tone  are  stimulated  again  by  the  second. 
A  tone  and  its  second  or  its  seventh  show  little,  or  no,  kin- 
ship, because  the  overtones  of  the  one   are  different    from 
those  of  the  other.     In  passing  from  the  one  to  the  other  of 
such  tones,  different  end-organs  are  stimulated.     Therefore 
the  tones  have  nothing  in  common. 


-  fi*j  +t**<*£***fa 

-» 

CHAPTER   VIII 
VISUAL   SENSATIONS 

The  eye  furnishes  us  by  far  the  greatest  number  and 
variety  of  sensory  experiences  of  all  the  sense-organs.  The 
sensitive  end-organs  which  give  these  visual  sensations  are 
the  rods  and  cones  of  the  retina.  The  eyeball  with  all  its 
parts  acts  as  a  camera  obscura  to  bring  the  rays  of  light  from 
outer  objects  to  a  focus  upon  the  sensitive  end-organs.  It 
has  three  coverings:  (i)  The  sclera,  an  outer  protective  coat, 
extending  into  and  forming  the  transparent  cornea  in  front; 
(2)  the  choroid,  the  color  coat,  whose  dark  pigment  excludes 
all  the  light  from  the  inner  chamber,  except  that  which 
enters  through  the  pupil,  a  round  adjustable  opening  in  the 
choroid;  and  (3)  the  retina,  the  thin  inner  lining  of  the  eye- 
ball, containing  the  sensitive  rods  and  cones  connected  with 
the  fibres  of  the  optic  nerve,  which  are  distributed  here  for 
the  purpose  of  transmitting  impulses  to  the  brain.  The  re- 
fractive media  of  the  eye  are:  (i)  The  cornea,  the  transparent 
covering  in  front;  (2)  the  aqueous  humor,  a  lymph-like  fluid 
filling  the  anterior  chamber  of  the  eyeball;  (3)  the  crystalline 
lens,  a  clear,  transparent  body,  biconvex  in  shape,  enclosed 
in  a  thin,  elastic  capsule  and  attached  to  the  suspensory  liga- 
ment; and  (4)  the  vitreous  humor,  a  jelly-like  body  filling  the 
back  part  of  the  eyeball.  These  media  are  sufficient  when 
the  eye  is  at  rest  to  bring  the  parallel  rays  from  objects  more 
than  20  to  30  feet  distant  to  a  focus  on  the  retina.  For 
nearer  objects  the  crystalline  lens  changes  its  curvature  to 
suit  the  distance,  becoming  more  and  more  convex  as  objects 
approach  and  less  convex  as  objects  recede  from  the  eye. 
This  adjustment  of  the  lens  for  near  and  far  objects  is  termed 
accommodation. 

166 


VISUAL   SENSATIONS 


167 


Accommodation  for  near  objects  is  brought  about  by  the 
action  of  the  ciliary  muscle,  which  by  contracting  lessens  the 
strain  of  the  suspensory  ligament  on  the  lens  and  allows  it 


Pupil 


Ciliary 
Body 


Posterior 
'Chamber 


Conjunctiva 


ic  Nerve 


FIG.  53. — Horizontal  section  through  the  left  eye. 

by  its  own  elasticity  to  become  more  convex.  For  far  ob- 
jects the  ciliary  muscle  relaxes,  allowing  the  eyeball  to  bulge 
outward,  and  so  by  pulling  on  the  suspensory  ligament  flat- 
tens the  lens. 

By  means  of  six  muscles  attached  to  the  external  coat  of 


I 68  PSYCHOLOGY 

the  eyeball  the  eyes  are  revolved  in  their  sockets  so  that 
they  may  be  directed  in  different  directions.  For  far  objects 
the  lines  of  sight  for  the  two  eyes  are  practically  parallel, 
but  for  near  objects  they  converge.  In  looking  from  a  near 
object  to  one  farther  away,  the  lines  of  sight  diverge,  i.  e.,  be- 
come less  convergent.  These  acts  of  adjustment  are  known 
as  convergence  and  divergence.  The  acts  of  convergence,  diver- 
gence, and  accommodation  take  place  reflexly. 

The  Retina. — The  thin,  transparent  retina  extends  for- 
ward almost  to  the  ciliary  process,  so  that  it  covers  all  the 
inner  surface  of  the  eyeball,  upon  which  images  of  objects 
can  fall.  There  are  many  different  layers  or  differentiated 
structures  in  the  retina,  which  the  microscope  is  able  to 
reveal.  Of  these  the  rods  and  cones  are  of  most  interest  to 
us  because  they  are  the  end-organs  which  receive  the  light- 
stimuli  and  generate  the  nervous  impulses  which  are  sent  to 
the  brain  centres,  resulting  in  sensations  of  light  and  color. 
The  rods  and  cones  are  turned  away  from  the  source  of  light, 
making  it  necessa^foj  fog  '  llght-r^yc;  fa  iy»T?Ai"ra  ***.*"  the 
layers  of  the  retina  before  falling  upon  them.  Under  certain 
conditions  me  shadows  cast  by  the  blood-vessels  in  the  inner 
layer  of  the  retina  can  be  seen,  showing  that  the  part  of  the 
retina  which  receives  impressions  lies  on  the  side  of  the  retina 
away  from  the  source  of  light  and  back  of  the  retinal  blood- 
r  vessels.  If,  in  a  lighted  room,  a  candle  is  held  close  but  to 
r,  one  side  of  the  eye,  and  if  while  one  is  peering  into  the  dark- 
ness  the  candle  is  moved  slightly  but  rapidly  to  and  fro,  a 
network  of  dark  branching  lines  will  be  seen.  This  is  known 
as  Purkinje's  network. 

In  the  centre  of  each  retina,  directly  opposite  the  pupil, 
there  is  a  small  yellow  spot  (macula  lutea),  within  which  is 
found  a  pit- like  depression  called  the  fovea  centralis.  Here  the 
cones  are  directly  exposed  to  light-rays  because  the  inner 
layers  and  blood-vessels  are  pushed  aside  to  form  the  pit  of 
the  fovea.  It  is  upon  the  foveatfiat  the  images  of  objects 
are  focussexLiii.. direct  vision.  TheTovearls  themost  sensitive 


VISUAL   SENSATIONS 


169 


part  of  the  retina,  and  therefore  gives  the  most  distinct 
vision.  In  looking  at  an  object  we  reflexly  turn  the  eyes 
so  that  its  light-rays  fall  upon  the  fovea. 

The  distribution  of  the 
rods  and  cones  in  the 
retina  is  not  uniform. 
There  are  no  rods  in  the 
fovea  centralis.  Only 
cones  are  found  there. 
They  decrease  in  num- 
ber, however,  as  we  pass 
toward  the  periphery  of 
the  retina,  where  the  rods 
greatly  predominateT 
Movement  of  objects  is 
sensed  more  quickly  by 
the  outer  parts  of  the 
retina,  while  accurate 
vision  is  best  at  the  fo- 
vea. The  fact  that  the 
periphery"  of  the^yg  15 
most  sensitive  to 'move- 


ment probably  has  a  bio- 
logical significance!  Sen- 
sitiveness  to  the  approach 
of  danger  from  behind  or 
frorri  the  sides  gave  or- 
ganisms a  great  advan- 
tage in  their  ability  to 
survive.  Man  has  evi- 
dently shared  in  this 
sensitiveness  to  movement  in  indirect  vision. 


FIG.  54. — Diagrammatic  section  of  the 
retina.  (After  Greeff).  I,  Pigment  epi- 
thelium; II,  rods  and  cones.  Outside 
the  fovea  the  rods  and  cones  are  both 
found,  in  the  fovea  only  con^s.  Ill, 
IV,  V,  VI,  VII,  show  intermediate 
neurones  and  nerve  connections.  From 
the  neurones  at  VIII  the  optic  fibres 
pass  out  as  indicated  at  IX  toward  the 
optic  disc  where  they  leave  the  eyeball 
to  form  the  optic  nerve;  X  limiting 
membrane  of  retina.  A  ray  of  light 
entering  the  eye  passes  through  the 
retina  from  X  to  II. 


The  periphery 


retina  is,  less  sensitive  to  color;  in  fact,  the  extreme 


outer  portion  is  color-blind. 

The  optic  nerve  enters  each  eyeball  on  the  nasal  side  of 
and  at  a  point  not  far  from  the  fovea  centralis.     At  its  point 


170  PSYCHOLOGY 

of  entry,  known  as  the  optic  disc,  there  are  no  rods  and 
cones;  consequently,  no  vision  is  possible  there.  For  that 
reason  the  optic  disc  is  commonly  known  as  the  blind  spot. 


FIG.  55. — Close  the  left  eye.  Fixate  the  cross  in  the  figure.  When  the  book 
is  a  little  over  eight  inches  from  the  eye,  the  dot  will  disappear.  Slowly 
move  the  book  farther  away  until  the  square  disappears.  The  eye  must  be 
steadily  fixed  upon  the  cross.  The  explanation  of  the  inability  to  see  the 
figures  is,  of  course,  found  in  the  fact  that  they  fall  upon  the  blind  spot. 
(From  Thorndike's  "  Elements  of  Psychology.") 


FIG.  56. — Notice  that  when  the  white  disc  in  the  black  square  falls  upon  the 
blind  spot  it  is  filled  in  with  the  black  of  its  surrounding  background.  In 
order  to  project  the  disc  upon  the  blind  spot,  close  the  left  eye  and  fixate 
the  cross  with  the  right  eye.  The  book  should  be  held  about  eight  inches 
from  the  eyes  with  the  cross  directly  in  front  of  the  right  eye. 

(From  Thorndike's  "  Elements  of  Psychology.") 


The  iris  of  the  eye  functions  in  the  same  way  as  the  dia- 
phragm of  a  camera.  By  contracting  and  expanding  it  varies 
the  size  of  the  pupil,  thus  controlling  the  amount  of  light 
entering  the  eye.  If  too  much  light  enters,  the  pupil  becomes 
smaller;  if  not  enough,  it  becomes  larger.  This  action  of  the 


VISUAL   SENSATIONS 


171 


iris  is  a  pure  physiological  reflex,  known  as    the  pupillary 
reflex.     It  is  set  off  by  the  action  of  light  upon  the  eye. 

The  power  of  the  resting  eye,  as  an  optical  instrument, 
is  such  that  parallel  rays  (rays  from  distant  objects)  are 
brought  to  a  focus  upon  the  retina.  In  order  to  form  clear 
images  of  nearer  objects  whose  rays  are  divergent,  the  cur- 
vature of  the  lens  jnust^be  changed  by  the  act  of  accommoda- 


FIG.  57. — The  change  of  the  lens  in  accommodation.  (From  Ladd  and  Wood- 
worth,  after  Helmholtz.)  The  left  half  of  the  figure  shows  the  lens  focussed 
on  a  distant  object,  the  right  half  on  a  very  near  object,  c,  the  ciliary 
muscle;  s,  the  suspensory  ligament. 


tion.  In  this  case  the  front  surface  of  the  lens  bulges  for- 
ward, making  the  lens  more  convex,  thus  increasing  its  focal 
power.  This  is  illustrated  in  the  accompanying  cut. 

The  limits  of  accommodation  vary  with  the  condition  of 
the  eyes  and  with  age.  The  young,  elastic  lens  can  accom- 
modate for  a  distance  of  about  7  to  10  cm.  In  presbyopia, 
inelasticity  of  the  lens  attendant  upon  old  age,  the  near  limit 
of  accommodation  may  be  increased  to  50  or  60  cm.  This 
limit  may  be  determined  very  roughly  by  closing  one -eye 
and  holding  up  a  pin  before  the  other  eye,  and  after  getting 
a  clear  image  moving  it  toward  the  eye  until  the  image  begins 
to  blur.  The  lens  is  not  able  to  bring  the  light-rays  to  a 
sharp  focus  upon  the  retina  nearer  than  this  point. 

If  the  eyeball,  from  the  retina  to  the  lens,  is  too  long,  or 
if  the  refractive  surfaces  of  the  lens  or  cornea1  are  too  great 

1  The  cornea  also  acts  as  a  refractive  medium. 


172  PSYCHOLOGY 

in  curvature,  the  rays  from  distant  objects  are  brought  to  a 
focus  in  front  of  the  retina  and  are  diverging  when  they 
reach  it,  blurring  the  image.  Only  near  objects  can  be  seen 
clearly.  This  condition  is  called  myopia,  or  near-sightedness. 
Concave  glasses  will  correct  the  difficulty.  If,  on  the  other 
hand,  the  eyeball  is  too  short,  or  the  curvature  of  the  lens 
and  cornea  is  not  great  enough,  light-rays  are  brought  to  a 
focus  back  of  the  retina.  This  is  called  hyperopia,  or  far- 
sightedness. By  wearing  convex  glasses  the  light-rays  are 
brought  to  a  focus  at  the  retina.  Another  condition,  known 
as  astigmatism,  is  caused  when  the  refractive  surfaces  (usually 
the  cornea)  are  not  perfectly  curved.  When  this  is  the  case 
the  rays  from  one  part  of  an  object  may  be  properly  formed 
on  the  retina,  while  other  rays  are  not,  resulting  in  a  badly 
focussed  image  and  constant  eye-strain. 

The  image  of  an  object  upon  the  retina  is  upside  down. 
The  fact  that  we  see  the  object  right  side  up,  although  its 
retinal  image  is  upside  down,  offers  no  difficulty  when  we 
consider  that  we  are  not  conscious  of  the  retinal  image  itself. 
The  spatial  relations  of  up  and  down,  right  and  left,  are  a 
matter  of  association  entirely.  We  perceive  as  "up"  that 
part  of  an  object  to  which  the  hand  must  be  raised  in  touch- 
ing or  grasping  it. 

The  Optic  Nerve  and  Optic  Centres. — The  nerve-fibres 
from  all  parts  of  the  retina  are  brought  together  at  the  optic 
disc  and  there  leave  the  eyeball  as  the  optic  nerve.  The 
nerves,  one  from  each  eye,  pass  backward  and,  joining  to- 
gether, form  the  optic  chiasma,  or  optic  commissure.  Here 
each  nerve  divides,  one  half  going  to  the  right  brain  and  the 
other  going  to  the  left  brain.  Part  of  the  fibres  from  each 
retina,  those  from  the  outer  or  temporal  halves,  pass  to  the 
same  sides  of  the  brain,  while  the  other  fibres,  those  from 
the  inner  or  nasal  halves  of  the  retinae,  cross  over  in  the 
chiasma  and  pass  to  the  opposite  sides  of  the  brain.  Accord- 
ing to  this  arrangement,  the  fibres  from  the  temporal  half  of 
the  right  eye  and  the  nasal  half  of  the  left  eye  go  to  the  right 


L.T.F. 


R.N.F. 


L.O.S.    L.O.D. 


FIG.  58. — Scheme  of  the  mechanism  of  vision.  (James  after  Seguin.)  The 
cuneus  convolution  (CM.)  of  the  right  occipital  lobe  is  supposed  to  be  injured, 
and  all  the  parts  which  lead  to  it  are  darkly  shaded  to  show  that  they  fail 
to  exert  their  function.  P.O.  are  the  intra-hemispheric  optical  fibres.  P.O.C. 
is  the  region  of  the  lower  optic  centres  (corpora  geniculata  and  quadrige- 
mina).  T.O.D.  is  the  right  optic  tract;  C,  the  chiasma;  F.L.D.  are  the 
fibres  going  to  the  lateral  or  temporal  half  T.  of  the  right  retina,  and  F.C.S. 
are  those  going  to  the  central  or  nasal  half  of  the  left  retina.  O.D.  is  the 
right,  and  O.S.  the  left,  eyeball.  The  rightward  half  of  each  is  therefore 
blind;  in  other  words,  the  right  nasal  field,  R.N.F.,  and  the  left  temporal 
field,  L.T.F.,  have  become  invisible  to  the  subject  with  the  lesion  at  Cu. 
(From  Angell's  "  Psychology.") 


1 74  PSYCHOLOGY 

brain,  while  the  fibres  from  the  temporal  half  of  the  left  eye 
and  the  nasal  half  of  the  right  eye  go  to  the  left  brain.  Ac- 
cordingly, light-stimuli  from  objects  on  the  left  side  of  the 
body  (falling  upon  the  right  half  of  each  retina)  send  their 
impressions  to  the  right  brain,  while  impressions  from  objects 
on  the  right  side  of  the  body  go  to  the  left  brain.  After 
leaving  the  optic  chiasma  the  nerve-fibres  go  to  the  mid- 
brain,  where  they  terminate  in  the  optic  thalami,  external 
geniculate  bodies  and  the  superior  quadrigemina.  There 
they  make  connections  with  another  set  of  fibres,  which  pass 
to  the  cuneus  convolutions  of  the  occipital  lobes,  which  con- 
stitute the  cortical  centres  for  vision.  The  right  occipital 
cortex  contains,  then,  the  centre  for  the  right  halves  of  the 
retinae,  while  the  left  occipital  lobes  contain  the  centre  for 
the  left  halves  of  the  retinae. 

If  one  of  the  optic  nerves  should  be  cut,  complete 
blindness  of  the  corresponding  eye  would  result.  But  if 
one  of  the  optic  tracts  should  be  cut  it  would  cause  blind- 
ness in  one  half  of  each  eye,  or  hemianopsia,  as  it  is  called. 
A  lesion  in  one  of  the  occipital  lobes  may  also  cause  hemia- 
nopsia. 

From  this  brief  description  of  the  eye  and  its  connections 
with  the  brain,  we  see  that  it  is  a  wonderfully  arranged  pho- 
tographic instrument  whose  many  parts  all  conspire  to  the 
one  end  of  producing  a  clear  image  of  outer  objects  upon  the 
sensitive  retina.  It  is  very  evident  that  the  image  itself  is 
j  iioJ^ejitUa-t]ie_bmin.^  Some  physiological  process  in  the  end- 
organs  must  intervene  between  the  image  and  the  impulses 
which  go  to  the  cortical  centres.  Just  what  that  process  is, 
is  a  matter  of  conjecture,  as  we  shall  see  when  we  take  up 
the  color  theories.  It  has  long  been  supposed  that  it  is 
^/  chemical  in  nature.  So,  when  it  was  discovered  that  the 
«^  outer  ends  of  the  rods  became  strongly  tinged  with  a  purple 
substance  when  light  was  excluded  from  the  eye,  and  that 
*  this  substance,  known  as  visual  purple,  bleached  very  rapidly 

when  exposed  to  light,  and  regained  its  purplish-red  color 


VISUAL   SENSATIONS 


175 


again  whenever  light  was  withdrawn  from  it,  it  was  thought 
that  the  true  visual  process  had  been  discovered.  Another 
fact  appeared  to  fortify  this  supposition,  namely,  that  some 
of  the  colored  light-rays  bleach  this  visual  purple  more  rap- 
idly than  others.  This  would  seem  to  provide  a  physiologi- 
cal basis  for  the  qualitative  differences  in  colors.  But  the 
fact  that  visual  purple  is  not  found  on  the  fovea,  the  area  of 
clearest  vision  and,  moreover,  that  vision  is  not  diminished 
after  the  visual  purple  is  exhausted,  make  it  highly  improb- 
able that  the  activity  of  the  visual  purple  is  the  real  visual 
process.  However,  a  number  of  facts  indicate  that  the  visual 
purple  increases  the  sensitivity  of  the  eye  in  very  dim  illu- 
mination, i.  e.,  in  twilight  vision.  It  is  a  very  common  ob- 
servation that  when  we  pass  from  a  very  light  room  into  the 
dim  illumination  of  the  night,  at  first  we  are  unable  to  see  at 
all.  But  gradually  the  eye  adapts  itself  to  the  darkness,  so 
that  we  can  see  well  enough  to  get  about.  Or,  when  passing 
from  the  dark  into  a  lighted  room,  the  light  is  at  first  so  bril- 
liant that  a  short  period  of  light-adaptation  is  necessary  be- 
fore the  eye  can  react  properly.  It  is  quite  probable  that 
the  building  up  of  the  visual  purple  on  the  rods  in  the  dark 
makes  them  more  sensitive  to  dim  light,  and  that  by  its 
means  the  eye  becomes  "dark-adapted."  It  is  known  that 
the  visual  purple  builds  up  more  slowly  than  it  bleaches  out, 
which  is  in  agreement  with  the  fact  that  the  eye  adapts  itself 
more  slowly  to  the  dark  than  to  the  light.  Still  another  in- 
teresting fact  to  be  considered  in  this  connection  is  that  the 
fovea,  which  contains  only  cones  and  no  visual  purple,  is 
practically  blind  in  very  dim  light.  All_this  makes  it, very 


probable  that  the  frincjion_of  the  purple_isirLo  increase  the 
sensitivity  of  thero^sto^dim^light.  The  eyes  of  "bats  and 
other  noc^urn^anim^Is^havepractically  no  cones,  but  the 
rods,  which  are  present  in  great  numbers,  are  liberally  sup- 
plied with  visual  purple. 

It  seems,  therefore,  that  the  rods  and  cones  of  the  eye 
perform  different   functions:   the  rods  for  twilight  and   the 


PSYCHOLOGY 

cones  tf  or  daylight  vision.  The  rods  give  sensations  of  light 
the  illumination  is  too  low  to  stimulate  the  cones  to 
It  is  also  probable  that  the  rods  furnish  us  with 
of  brightness  or  colorless  light  only,  and  that  the 
cpnes  furnish  us  with  our  color-sensations  in  addition  to  sen- 
j*  ^sfcftions  of  brightness  of  moderate  intensity.  In  very  dim 
y*  tfr  light  (deep  twilight),  when  the  fovea  is  blind,  no  color  can 
be  seen.  All  colors  then  appear  as  gray.  The  sensitivity  of 
the  eye  to  color  is  greatest  at  the  fovea,  and  decreases  as  the 
cones  decrease  in  number  toward  the  periphery,  where  the 
eye  is  absolutely  color-blind.  There  are  other  facts  which 
point  in  the  same  direction,  but  these  are  sufficient  to  indi- 
cate a  differentiation  of  the  rods  and  cones  with  regard  to 
light-sensations. 

Stimulus. — The  adequate  stimulus  for  visual  sensations  is 
the  vibrations  of  ether,  which  is  supposed  to  be  the  medium 
by  means  of  which  light  is  transmitted.  The  eye  may  be 
stimulated  inadequately  by  purely  mechanical  and  electrical 
energy.  A  blow  on  the  head  may  cause  us  to  see  stars,  or 
fill  the  field  of  vision  with  sudden  light.  By  pressing  upon 
the  outer  surface  of  the  closed  eye,  phosphenes,  or  circles  of 
light,  may  be  seen  in  the  inner  field  of  vision.  An  electric 
current  will  also  arouse  sensations  of  light  when  passed 
through  the  eyes.  The  physiological  processes  which  are 
/going  on  in  the  retina  ItselTalso  act  as  a  stimulus.  On  clos- 
ing the  eyes  and  covering  them  to  exclude  all  external  light, 
we  find  that  instead  of  absolute  darkness  the  eye  is  dimly 
illuminated  with  its  own  light  (Eigenlichf),  giving  an  ever- 
changing  cloud  effect. 

But,  as  we  have  said,  the  normal  stimulus  is  the  wave 
movement,  or  vibrations  of  ether.  The  eye  is  sensitive  only 
to  the  ether-vibrations  which  lie  between  the  infra-red  and 
the  ultra-violet  vibrations.  Ether-rays  below  the  red  and 
above  the  violet  arouse  no  visual  sensations,  although  they 
are  known  to  exist.  The  light-rays  that  stimulate  the  eye 


VISUAL   SENSATIONS 


177 


are  all  contained  in  the  spectrum,  whose  vibration  rates  are 
approximately  as  follows: 

Fraunhofer  line  B,  Red,  450  trillion  vibrations  per  second 

C,  Orange,  472 

D,  Yellow,  526 

E,  Green,  589 

F,  Blue-green,  640 

G,  Blue,  722 
H,  Violet,  790 

By  inspecting  the  colors  of  the  spectrum  the  student  will 
see  that  each  color  is  spread  out  in  a  narrow  band.  A  single 
vibration  rate  cannot,  therefore,  adequately  represent  a  color, 
for  any  color  may  have  a  number  of  different  vibration  rates. 
For  instance,  red  is  practically  the  same  in  appearance  from 
440  trillion  to  460  trillion  vibrations. 

The  red  rays,  the  slowest  in  vibration  rates,  are  the  long- 
est waves,  while  the  more  rapid  violet  waves  are  the  shortest 
in  length.  The  waves  vary  in  length  from  red,  0.000687  mm., 
to  violet,  0.000393  mm. 

Thus  we  see  that  the  quality  (hue)  of  sensations  of  color 
depends  upon  the  wave-lengths,  or  the  vibration  frequencies 
of  light.  For  example,  vibration  frequencies  ranging  around 
450  trillion  per  second  give  the  sensation  of  red,  while  those 
of  589  trillion  give  green.  But  the  correspondence  of  change 
of  vibration  rate  and  change  of  hue  is  not  uniform  in  all 
parts  of  the  spectrum.  At  the  lower  end  considerable  change 
in  the  number  of  vibrations  is  required  to  cause  a  change 
in  the  quality  of  red.  Green,  on  the  other  hand,  changes  its 
quality  very  rapidly,  corresponding  to  a  smaller  change  in 
the  vibration  rate  of  the  stimulus. 

When  homogeneous  light-rays  (light-rays  of  the  same 
length,  or  of  the  same  vibration  frequency)  fall  upon  the 
cones,  the  resulting  sensation  is  a  pure  color.  But  if  the 
light-rays  of  all  the  differing  frequencies  are  mixed,  the  result- 
ing sensation  is  white.  We  may  say  in  general  that  for  nor- 


1 78  PSYCHOLOGY 

mal  daylight  vision  homogeneous  or  pure  light-rays  are  the 
stimuli  for  the  pure  color-sensations;  while  a  mixture  of  all  the 
light-rays  is  the  stimulus  for  the  achromatic  or  colorless  sen- 
sations.1 

The  colorless,  white  light  of  sunlight  is  a  mixture  of  all 
the  light-rays.  When  a  beam  of  colorless  light  is  passed 
through  a  prism,  its  different  rays  are  bent  at  slightly  differ- 
ing angles,  thus  splitting  up  the  complex  white  light  into  its 
constituent  elements  and  forming  the  spectrum. 

^VT  Kinds  of  Visual  Sensations. — Visual  sensations  fall  into 
two  general  groups:  (i)  The  achromatic  and  (2)  the  chromatic. 
The  achromatic  or  colorless  sensations  form  a  series  from 
white  through  gray  to  black.  Although  there  is  a  difference 
of  opinion  on  the  subject  among  psychologists,  we  shall  con- 
sider white  and  black  as  different  qualities  of  colorless  sensa- 

v«£tions,  and  gray  as  a  compound  of  white  and  black.     The 

VyJ^achromatic  sensations,  however,  have  but  one  stimulus  (col- 

>r§WJiorless  light),  which  exists  in  various  degrees  of  intensity. 

V\**\  Black  is  the  result  of  a  very  low  degree,  gray  of  a  medium 
degree,  and  white  of  a  very  high  degree  of  intensity  of  color- 
less light.     It  has  been  suggested  that  black  is  the  absence  of 
light-stimulation  (the  resting  condition  of  the  retina),  and 
i    xtherefore  corresponds  to  inactive  brain  centres,  or  at  least 
brain  centres  which  are  receiving  no  nervous  impulses  from 
i    the   retina.     This   negative   conception   seems   unjustifiable. 
,'         Every  sensation  is  the  result  of  stimulation  of  some  end- 
<: organ  and  is,  therefore,  a  positive  experience.     Even  when 
we  first  enter  the  blackness  of  an  absolutely  light-proof  dark 
room,  where  no  external  stimulus  can  reach  the  eye,   the 
physiological  processes  of  the  retina  itself  cause  minimal  sen- 
sations of  light,  ordinarily  considered  as  black.     As  soon  as 
the  eye  becomes  dark-adapted,   the  black  becomes  lighter. 
The  ordinary  blacks  which  we  see  in  the  outer  world  are 
certainly  the  results  of  stimulation  of  the  retina.     The  nega- 
tive conception  would  make  "seeing  black"  equivalent  to 
1  Certain  modifications  will  be  made  to  this  general  statement  later. 


VISUAL   SENSATIONS 


179 


seeing  nothing  at  all  (blindness).  However,  "seeing  black" 
is  quite  different  from  "being  blind."  An  object  may  trans- 
mit a  considerable  amount  of  light  to  the  eye  and  yet  appear 
black.  Moreover,  there  is  not  a  single  black,  but  many  dif- 
ferent blacks,  as  he  who  has  been  commissioned  to  match  a 
given  black  fabric  at  the  dress-goods  counter  well  knows. 

Besides  the  usual  method  of  arousing  sensations  of  the 
white-gray-black  series,  namely,  stimulation  by  light-rays  of 
all  wave-lengths  acting  simultaneously  upon  the  retina,  there 
are  several  other  means  of  arousing  them:  Any  two  comple- 
mentary colors  when  mixed  will  produce  gray;  very  small 
areas  of  colors,  or  any  color  in  very  faint  light,  or  color  fall- 
ing on  the  periphery  of  the  eye  will  be  seen  as  gray. 

The  chromatic  sensations,  or  sensations  of  color,  form  a 
very  large  group  of  sensory  experiences,  not  only  the  experi- 
ences of  the  colors  of  the  spectrum,  but  also  the  thousands 
of  tints,  shades,  and  mixtures,  which  are  derived  from  them. 
The  spectral  colors  themselves,  or  rather  the  sensations  which 
we  get  from  them,  are  not  all  elementary.  Considering  the 
colors  of  the  spectrum,  beginning  at  the  lower  end,  we  have 
red,  orange,  yellow,  green,  blue,  indigo^blue,  and  violet.  It 
is  evident  that  orange  partakes  of  the  qualities  of  red  and 
yellow,  and  that  indigo-blue  and  violet  are  mixtures  of  blue 
and  red.  This  leaves  red,  yellow,  green,  and  blue  as  the  ele- 
mentary sensations  of  color.  Each  one  of  these  four  colors 

«*>MMBp>IBI^IMaKMaaM_|_MMM_MMI>HMMMMI>> 

possesses  a  color  quality  totally  niff^ent  ftom  the  others,  and 

each   quality   is  simple  and  unanalyzable.     There  are,  then, 


just  four  kinds  of  color-sensations — red,  yellow,  green,  and 
blue.  All  others  are  compounds,  formed  out  of  the  elemen- 
tary sensations.  This  classification,  being  purely  psychologi- 
cal, does  not  in  any  way  conflict  with  the  classifications  of 
the  colors  made  for  other  purposes.1 

1  The  artist  classifies  colors  into  three  primary  colors — red,  yejjojv,  and 
b^ue.     The  physicist  also  reduces  colors  to  three — red,  gregrj^and  bhj&jop.let,  ^ 
which  he  names  fundamental  colors.     The  physiologist  speaks  of  four  colors 
(purple-red,  bluish  green,  blue,  and  yellow)  as  invariable  or  staple  colors. 

««IMM»NMMM^»  ** 


180  PSYCHOLOGY 

Brightness  of  Colors. — The  spectral  colors  are  not  all  of 
equal  brightness.  In  ordinary  daylight  illumination,  yellow 
is  the  brightest  and  violet  the  darkest  color,  i.  e.,  yellow  is 
nearest  and  violet  farthest  away  from  white.  Since  the  grays 
form  a  series  of  increasing  brightness  from  black  to  white,  it 
is  possible  to  match  the  brightness  of  any  one  of  the  colors 
with  some  degree  of  gray.  In  this  way  we  can  determine 
the  brightness  of  the  colors.  We  shall  find  that  yellow  will 
correspond  in  brightness  to  a  gray  which  stands  higher  up 
(nearer  white)  than  the  gra'y  which  corresponds  with  any  of 
the  other  colors.  Violet  corresponds  with  a  gray  lower  down, 
i.  e.,  farther  away  from  white.  (See  the  color  pyramid, 
Figure  59.)  Now,  if  the  illumination  of  the  spectrum  is  in- 
creased in  intensity,  all  sensations  of  color  tend  to  disappear 
and  the  spectrum  appears  washed  out  or  whitish,  and  at 
the  maximum  intensity  all  colors  become  white.  Yellow 
and  blue  hold  their  colors  longest.  If,  on  the  other  hand,  the 
illumination  (brightness)  of  the  colors  is  reduced,  the  colors 
become  darkened  and  finally  change  into  colorless  lights  of 
low  intensity.1  In  general,  then,  we  may  say  that  when 
I  color-stimuli  become  sufficiently  fa.tfihse,  the  coIofS  afe*  Se'en 
!as  white;  if  they  become  sufficiently  feeble,  colors  are  seen  as 
•dark  gray  or  black. 

Purkinje  Phenomenon. — An  interesting  fact,  known  as 
Purkinje's  phenomenon,  may  be  observed  when  the  eye  be- 
comes dark-adapted  and  the  illumination  of  the  spectral 
colors  reduced  to  a  minimum.  In  ordinary  light,  when  the 
eye  is  light-adapted,  the  brightest  color  in  the  spectrum  is 
yellow,  but  when  the  illumination  is  very  dim  and  the  eye 
becomes  dark-adapted,  the  region  of  maximum  brightness 
changes  from  the  yellow  to  the  green.  The  reds  become  rela- 
tively darker,  while  the  blues  become  brighter.  This  change 
of  brightness  takes  place  only  when  the  eye  becomes  dark- 
adapted,  and  consequently  it  does  not  occur  in  foveal  vision. 
The  Purkinje  phenomenon,  therefore,  appears  only  when  the 

1  Red  appears  to  hold  some  of  its  color  until  it  disappears  altogether. 


VISUAL   SENSATIONS  l8l 

eyes  shift  from  daylight  to  twilight  vision,  and  become  dark- 
adapted. 

It  is  interesting  to  note  in  this  connection  that  when  a 
dark-adapted  eye  is  exposed  to  different  colored  lights,  the 
visjoaLpurple-is- -bleached  .most  iapidly~by-green  light,  next  vf 
by  blue  light,  and  least  of  all  by  red  light.  This  may  explain 
the  relative  degrees  of  brightness  of  these  colors  in  a  dark- 
adapted  eye. 

Saturation. — It  is  quite  evident  that  there  is  considerable 
variation  in  each  of  the  four  kinds  of  color-sensations.     For 
instance,  there  are  many  colors  which  we  may  call  red,  many 
that  may  be  called  blue,  etc.,  but  the  purest  red,  the  saturated 
red,  is  found  in  the  spectrum.     Likewise,  all  the  other  colors 
are  purest  or  most  saturated  in  the  spectrum.     Saturation 
refeis_to  the  degree  of  purity  of  a  color,  its  freedom  from  ad- 
rnixtyre  wif>|   o^her  liyht-wavffi.     So  a  color  is  said  to  be 
saturated  when  it  contains  little  white  light— when  it  is  as     ./A>^ 
little  like  white  as  possible.     We  never  experience  absolutely  \ ^ v 
pure  or  completely  saturated  colors.     There  is  always  some  / 
white  light  in  any  color,  but  those  of  the  spectrum  are  the 
nearest  approach  to  saturation.     Of  these,  rgjjjjind  Ml?**  3Ift 
mos£,  while  yellow  and  green  are  the  least,  saturated. 

Complementary  Colors. — If  we  examine  the  spectrum,  we 
find  that  adjacent  colors  shade  off  into  each  other  gradually; 
red  shades  into  yellow  through  orange,  yellow  passes  into  v  \' 
green  through  greenish  yellow  and  yellowish  green,  green  into  f    .^ 
blue  through  bluish  green  and  greenish  blue,  and  blue  passes 
back  to  red  through  the  violets,  so  that  the  colors,  jn^paH  "f 
forming  a  straight  line,  may  be  arranged  in  a  circle1joj:_ra.ther 
as^aTsquare,  since  the  color  quality  changes  abruptly  four 
timesin  making  the__circuit  from  red  fcark   fr*  rprl   aga1'" 
Now,  between  any  two  adjacent  colors  lie  mixtures  of  the 
two  colors,  which  possess  the  color  qualities  of  both.     If, 
however,  we  select  pairs  of  colors  not  adjacent  to  each  other, 
such  as  yellow  and  blue,  there  is  no  way  of  passing  from  one 
to   the  other  through   intermediate  colors.     When  we  mix 


PSYCHOLOGY 


such  pairs  of  colors,  instead  of  giving  a  spectral  color  of 
intermediate  hue,  they  tend  to  neutralize  each  other  and 
produce  a  gray.  Such  colors  are  said  to  be  complementary 
colors.  Complementary  colors  are  those  colors  which,  when 

mixed,  give  gray.     Thus  yellow  and 
/1J\  blulT~"aT!e~~^mplementary     colors. 

Some  of  the  other  pairs  of  comple- 
mentary colors  are  red  and  bluish 
green,  orange  and  greenish  blue, 
green  and  reddish  purple. 

The  Color  Pyramid.— A  simple 
scheme  for  representing  the  rela- 
tions of  color-sensations  to  each 
other  and  to  the  white-gray-black 
series  can  be  made  by  arranging 
the  colors  in  the  form  of  a  double 
pyramid,  and  placing  the  grays 
along  the  axis  connecting  the  two 
poles. 

This  double  pyramid  represents 
the  two  systems  of  sensations — sen- 
sations of  light  and  sensations  of 
color.  Around  the  base  (or,  rather, 
where  the  bases  join)  we  may  ar- 
range the  saturated  colors  in  the 
In  fact,  we  may  consider  the  straight 

line  of  the  spectrum  bent  in  four  places  (in  the  red,  the 
yellow,  the  green,  and  the  blue),  to  form  a  square.  We 
may  add  purple  to  make  the  connection  between  violet 
and  red.  Along  this  line  lie  all  the  spectral  or  saturated 
^colors.  Orange  lies  between  red  and  yellow,  yellow-green 
y  between  yellow  and  green,  blue-green  between  green  and 
blue,  and  violet  and  purple  between  blue  and  red.  The 
eye  can  detect  from  150  to  160  different  spectral  colors. 
^ne  white-gray-black  series  is  arranged  along  the  straight 
line  joining  the  upper  apex  with  the  lower,  white  at  the  top 


^ 


FIG.  59. — The  color  pyramid. 

(From  Titchener's  "  Text-book  of 

Psychology.") 

order  of  the  spectrum. 


VISUAL  SENSATIONS  183 

and  black  at  the  bottom,  with  all  the  intermediate  grays 
between.  There  are  about  700  different  degrees  of  gray,  from 
the  whitest  white  to  the  darkest  black.  The  middle  gray  is 
at  the  point  where  the  line  joins  the  base.  Along  the  lines 
from  the  corners  of  the  base  to  the  upper  apex  lie  all  the 
tints  of  the  colors,  from  middle  brightness  to  white,  while 
along  the  lines  from  the  corners  to  the  lower  apex  lie  all  the 
shades  between  the  colors  and  black.  For  instance,  between 
blue  and  white  there  is  a  series  of  tints  of  blue,  which  start 
with  blue  of  middle  brightness  and  gradually  fade  out  into 
white.  Likewise,  between  the  blue  and  black  is  another 
series,  which  we  may  arbitrarily  name  "shades,"1  beginning 
with  blue  and  ending  with  black.  So  with  all  the  other 
colors  represented  on  the  base  of  the  double  pyramid.  If, 
now,  one  pass  from  a  saturated  color  on  the  outer  rim  of  the 
base  toward  the  centre  of  the  pyramid,  another  series  of 
colors,  becoming  less  and  less  saturated  and  ending  at  the 
centre  in  neutral  or  middle  gray,  is  represented. 

The  results  of  mixing  colors  are  roughly  indicated  in  the 
pyramid.  Mixtures  of  any  two  colors  lie  on  the  straight 
lines  between  the  colors  mixed.  If  red  and  yellow  are  mixed 
the  result  is  an  orange,  which  is  found  on  the  line  in  the 
pyramid  between  the  two  colors.  A  mixture  of  white  and 
black  gives  a  middle  gray.  If  two  complementary  colors, 
say  yellow  and  blue,  are  mixed,  the  result,  gray,  is  likewise 
found  on  an  imaginary  line  joining  the  colors  in  the  pyramid. 

The  difference  in  the  brightness  of  the  spectral  colors  is 
represented  by  the  angle  which  the  base  makes  with  the 
white-gray-black  line.  Yellow,  being  the  brightest  color,  is, 
therefore,  found  nearest  white  and  corresponds  in  brightness 
to  the  gray  represented  directly  opposite  on  the  dotted  line. 
Blue,  having  a  lower  degree  of  brightness,  is  farther  away 
from  white,  and  is,  therefore,  matched  with  a  gray  lower 
down  on  the  dotted  line. 

1  The  use  of  the  word  "shade"  in  this  restricted  meaning  is  purely  arbitrary 
and  technical. 


184  PSYCHOLOGY 

The  number  of  different  sensations  of  light  and  color, 
tints  and  shades,  and  their  mixtures,  which  the  eye  can  see 
and  which  must  be  represented  upon  the  surfaces  and  in  the 
volume  of  the  color  pyramid,  is  very  large.  It  has  been 
variously  estimated  from  33,000  upward. 

Color  Mixtures. — By  superimposing  two  different  colored 
lights  upon  the  same  retinal  surface  we  get  a  mixture  of 
the  two  colors.  The  simplest  way  to  mix  colors  is  to  place 
them  on  a  cardboard  disc,  which  can  be  made  to  revolve 
very  rapidly  on  a  color- wheel.  In  this  way  a  disk  having  two 
or  more  different  colors  will,  when  revolved  rapidly  enough, 
give  a  smooth,  even  color,  which  is  the  mixture  of  the  given 
colors.  For  instance,  if  a  disc  having  all  the  colors  on  it  is 
revolved,  the  result  is  an  even  neutral  gray.  If  a  disc  is 
half  red  and  half  yellow,  the  mixture  will  be  orange;  if  half 
yellow  and  half  blue,  the  mixture  will  be  a  gray,  and  so  on. 
Thousands  of  mixtures  of  saturated  colors,  tints,  and  shades 
with  each  other  and  with  the  whites,  grays,  and  blacks  may 
be  made  in  this  way.  The  most  important  principles  of 
color-mixing  are  as  follows:  (i)  When  complementary  colors 
are  mixed  in  the  proper  proportion  the  result  is  a  gray;  if 
not  in  that  proportion,  they  will  give  a  washed-out  or  un- 
saturated  color  of  the  same  quality  as  the  preponderating 
color.  Thus,  if  a  large  part  of  the  disc  is  blue  and  only  a 
small  part  yellow,  the  mixture  will  be  an  unsaturated  blue. 
(2)  When  colors  that  are  not  complementary  are  mixed,  the 
result  is  an  intermediate  color.  The  hue  will  vary  with  the 
relative  amounts  of  the  two  colors.  If  blue  and  green  are 
mixed,  the  result  is  an  intermediate  blue-green;  if  the  rela- 
tive amount  of  green  is  large,  the  mixture  will  be  a  green 
tinged  with  blue;  if,  on  the  other  hand,  blue  forms  the  larger 
part,  then  the  mixture  will  be  blue  tinged  with  green. 

Light  and  Color  Adaptation. — The  quality  of  a  light  or 
color  sensation  is  modified  by  the  length  of  time  the  stimulus 
has  acted  upon  the  retina.  This  is  due  to  the  adaptation  of 
the  end-organs  to  the  stimulus.  When  dark  glasses  are  first 


VISUAL   SENSATIONS  185 

put  on,  everything  appears  dark,  but  after  a  time  the  dark- 
ness wears  off.  Likewise,  when  colored  glasses  are  placed 
before  the  eyes,  their  color  is  strongly  marked,  but  later  it 
may  disappear  altogether  and  objects  will  appear  in  their 
normal  colors.  The  change  which  a  color  undergoes  as 
stimulus  continues  may  be  observed.  Look  steadily  at  a 
saturated  red  with  one  eye,  while  the  other  is  closed.  After 
one  minute  compare  the  red  seen  by  the  adapted  eye  with 
the  same  red  seen  by  the  non-adapted  eye.  The  red  of  the 
adapted  eye  appears  much  less  saturated  than  that  of  the 
non-adapted  eye.  If  color-stimuli  act  on  the  retina  for  a 
long  period,  they  become  less  and  less  able  to  arouse  color- 
sensations.  Brightness-stimuli  also  become  less  and  less  able 
to  arouse  their  original  sensations  as  they  continue  to  act. 
WP  mav  §§y  that,  a^  tha_proffigg|  nf  adaptation 


r  *f 


, 


an4_niore  toward  their  opposiies.  If  we  gaze  at  a  white 
cardboard  it  becomes  darker;  if  we  gaze  at  black  it  becomes 
lighter.  So  with  colors;  they  tend  to  lose  their  saturation 
as  the  stimulus  continues. 

The  effect  of  adaptation  to  any  light  and  color  stimulus 
not  only  blunts  the  sensitivity  for  the  given  stimulus,  but  it  j^,  w* 
also  increases  the  sensitivity  of  the  retina  for  the  opposite  or 
complementary  color.  When  we  go  from  the  yellow  lamp- 
light of  a  closed  room  into  the  daylight,  everything  looks 
bluish.  Gaze  steadily  at  a  sheet  of  yellow  paper  for  thirty  -T^u 
seconds,  then  at  a  neutral  gray  surface,  and  observe  that  the. 
gray  is  tinged  with  blue.  After  adaptation  to  any  color,  a 
neutral  gray  will  appear  to  possess  the  tint  of  the  comple- 
mentary color.  It  seems,  then,  that  any-light  or  color  stim- 
ulus sets  up  not  only  its  gym  ^tinai  process,  but  tends  also 
to  set  up  the  opposite  pror^s  This  tendency  shows  itself 
in  the  negative  after-images,  or  after-sensations,  of  light  and 
color.  If  we  fixate  a  small  blue  square  for  a  short  time  and 
then  look  at  an  even  gray  surface,  the  after-image  of  the 
square  will  appear  in  a  yellowish  tint.  The  negative  after- 


1 86  PSYCHOLOGY 

image  of  a  window  filled  with  sunlight  is  just  the  opposite 
of  the  original  sensations  in  distribution  of  light  and  dark 
parts;  the  panes  appear  dark  and  the  sashes  light.  Negative 
after-images  of  color  and  brightness  are  the  opposites  of  the 
original  sensations.  The  after-effect  of  adaptation  is  always 
in  the  opposite  direction. 

Successive  Contrasts. — The  tendency  of  visual  stimuli  to 
set  up  opposite  sensory  processes  is  responsible  for  the  so- 
called  successive  contrast  effects.  After  adaptation  to  white, 
a  dark  gray  appears  darker;  after  becoming  accustomed  to 
yellow,  blue  appears  bluer;  and  so  on.  That  is,  after  white, 
gray  is  darker,  and  after  yellow,  blue  is  bluer  "by  contrast," 
as  we  commonly  say. 

^-  Simultaneous  Contrasts. — In  successive  contrasts,  the  ef- 
fects are  wrought  upon  the  same  retinal  areas.  But  in  simul- 
taneous contrasts,  different  areas  of  the  retina  are  concerned. 
The  stimulation  of  one  part  of  the  retina  affects  or  modifies 
/vthe  action  of  other  parts.  Here,  as  in  adaptation,  the  con- 
:  trast  effect  is  in  the  opposite  direction.  For  instance,  a  small 
gray  square  surrounded  by  a  colored  field  always  appears 
tinged  with  the  color  complementary  to  the  surrounding  color. 
A  gray  surrounded  by  a  bluish  green  becomes  markedly  red- 
dish by  contrast.  The  blue-green  sets  up  the  complemen- 
tary color  process  in  the  part  of  the  retina  stimulated  by  the 
gray.  It  has  been  suggested  that  the  bluish-green  photo- 
chemical activity  of  the  surrounding  retinal  field  draws  from 
the  gray  re  anal  field  certain  chemical  substances  essential 
for  the  bluish-green  process,  and  leaves  the  gray  field  more 
sensitive  to  the  complementary  red  stimuli  which  are  present 
in  gray  light.  On  the  other  hand,  it  has  been  suggested  that 
the  contrast  effect 'is  of  central  origin  and  not  retinal  at  all. 

Besides  the  color  contrast,  we  also  have  the  brightness 
contrast.  A  small  gray  square  on  a.  white  background  will 
appear  much  darker  than  it  really  is.  On  a  black  background 
it  seems  much  lighter  than  it  really  is. 

Edge  contrasts  are  very  pronounced.     If  two  sheets  of 


VISUAL   SENSATIONS  187 

colored  papers,  saturated  red  and  green,  or  blue  and  yellow, 
are  placed  so  that  they  partly  overlap,  along  the  edges  where 
the  papers  meet,  three  will  appear  two  narrow  margins  of 
intense  color,  one  of  intense  red  on  the  red  paper  and  one  of 
intense  green  on  the  green  paper.  This  is  caused  by  slight 
eye-movement,  which  allows  a  small  strip  of  the  retina  which 
has  become  adapted  to  one  color  to  be  stimulated  momen- 
tarily by  the  complementary  color,  for  which  it  has  been 
made  more  sensitive  by  its  previous  stimulation;  hence  the 
increased  intensity  of  the  sensation. 

Most  marked  color  contrasts  are  seen  when  a  narrow 
strip  of  gray  paper  is  laid  across  several  sheets  of  paper  of 
the  different  spectral  colors,  and  over  all  of  which  is  placed 
a  larger  sheet  of  thin  tissue  paper.  The  gray  strip  then 
becomes  strongly  tinged  in  its  different  parts  with  the  colors 
complementary  to  its  several  backgrounds.  The  part  of  the 
strip  lying  over  the  blue  sheet  appears  to  be  yellow,  while  the 
part  over  the  yellow  sheet  is  blue;  over  the  red  sheet  it  ap- 
pears greenish  and  over  the  green  sheet  it  appears  reddish. 
This  is  usually  spoken  of  as  the  Meyer  Experiment. 

Contrast  effects  are  also  very  marked  in  shadows  cast  in 
colored  lights.  If  an  oil-lamp  is  lighted  in  daylight  the 
shadow  of  any  object  cast  on  an  uncolored  surface,  such  as 
that  of  a  white  table-cloth,  is  strongly  tinged  with  blue.  The 
shadow,  itself  gray,  is  surrounded  with  the  yellow  lamplight 
and  by  contrast  appears  blue. 

In  general,  contrasts  are  more  evident  the  nearer  together 
the  contrasting  surfaces  lie  and  the  more  nearly  they  are  of 
the  same  degree  of  brightness.  The  more  saturated  the 
colors  the  greater  the  color  contrast.  Differences  in  texture 
in  contrasting  surfaces  and  division  lines  or  boundaries  of 
any  kind  tend  to  destroy  contrasts.  It  should  be  noticed 
that  simultaneous  contrasts  are  set  up  immediately,  before 
adaptation  has  had  time  to  operate.  This  indicates  that 
contrasts  are  at  least  partly  independent  of  adaptation. 

It  is  evident  that  while  the  character  of  sensations  of 


I 88  PSYCHOLOGY 

brightness  and  color  is  primarily  determined  by  the  nature 
of  the  stimulus  (wave-length,  amplitude,  and  composition  of 
ligh t- waves) ,  nevertheless  these  sensations  are  modified  by 
contrasts  and  by  adaptation  of  the  sensory  end-organs. 

Color  Zones  of  the  Retina. — -We  may  call  attention  here 
to  the  differences  of  color  sensations  aroused  on  different 
parts  of  the  retina.  Ordinarily,  what  we  attend  to  in  the 
field  of  vision  falls  upon  the  central  part  of  the  retina,  and  so, 
unless  our  attention  is  especially  called  to  it,  we  are  unaware 
that  objects  in  the  outlying  parts  of  the  visual  field  are  always 
seen  without  color.  This  absence  of  color  is  explained  by 
the  fact  that  the  outer  zone  of  the  retina  is  totally  color- 
blind. By  means  of  the  "perimeter,"  the  parts  of  the  retina 
that  are  sensitive  to  color-stimulation  may  be  determined. 
Light  from  a  small  red  disc,  when  it  falls  upon  the  outer  zone 
or  periphery  of  the  retina  is  seen  as  black  or  very  dark  gray. 
If  the  disc  is  then  moved  so  that  its  image  approaches  the 
fovea  or  centre  of  the  retina,  it  will  change  to  a  yellow,  and 
finally  a  point  will  be  reached  nearer  the  fovea,  where  it  will 
be  seen  in  its  true  color.  So  with  the  other  elementary 
colors,  except  that  the  points  at  which  they  appear  in  their 
true  colors  differ. 

The  retina  has  three  zones  which  respond  differently  to 
color-stimuli.  Figure  60  shows  a  map  of  the  color  zones. 
The  color  zones  differ  somewhat  in  contour  for  different  in- 
dividuals, but  in  the  relative  positions  of  the  zones  they  are 
the  same. 

The  outermost  zone  responds  only  with  sensations  of 
colorless  light,  no  matter  what  the  nature  of  the  stimulus  is. 
The  intermediate  zone  gives  sensations  of  yellow  and  blue 
in  addition  to  white-gray-black;  while  the  innermost  zone 
responds  with  all  sensations  of  color  and  light.  With  stimuli 
of  equal  intensity  and  saturation,  the  red  and  green  zones 
tend  to  coincide;  likewise  the  yellow  and  blue.  So  we  may 
speak  of  the  green-red  zone,  the  yellow-blue  zone,  and  the 
white-black  zone.  These  zones  are  not  absolutely  fixed,  but 


R,  E. 


240 

^— — . 

27<T  270* 

FIG.  60. — Perimeter  chart  of  the  color  zones  of  the  retinae. 


27Q-  270° 

FIG.  61. — Color  zones  in  a  case  of  red-green  blindness. 


VISUAL    SENSATIONS  189 

vary  with  different  intensities  of  color-stimuli.  The  map 
here  given  was  made  with  stimuli  of  moderate  intensi- 
ties. 

Color-Blindness. — A  considerable  number  of  persons  are 
lacking  in  color-vision.  It  is  estimated  that  about  3^  per 
cent  of  the  male  and  2  per  cent  of  the  female  population  are 
color-blind.  The  most  common  form  of  abnormal  color- 
vision  is  partial  color-blindness  (dichromasia) ,  although  there 
are  a  few  cases  of  total  color-blindness  (achromasia) .  Partial 
color-blindness  almost  always  exists  as  red-green  blindness. 
Persons  thus  afflicted  are  unable  to  sense  red  and  green. 
They  see  all  the  colors  of  the  spectrum  as  yellows,  blues, 
and  grays.  They,  therefore,  live  in  a  world  of  two  colors 
only.  The  rgcjs,,,  j^rangggj  jrellpws,  cincl  jiaits.  oJLjbhe  greens 
appear  to  them  in  various  tones  of  yellow,  some  of  the  greens 
and  blues  that  lie  next  to  each  other  in  the  spectrum  appear 
as  gray,  while  the  rest  of  the  blues  and  the  violets  appear  as 
blue.  In  other  words,  they  see  the  spectrum  as  a  band  of 
yellows  in  its  lower  part  and  a  band  of  blues  in  its  upper 
part,  with  a  narrower  band  of  gray  between.  Some  of  the 
reds  at  the  lower  part  of  the  spectrum  are  also  gray  for  the 
color-blind.  The  red-green  blind,  therefore,  confuse  red  and 
green.  If  such  a  person  were  asked  to  match  a  red  from  a 
pile  of  many-colored  yarns,  he  would  pick  out  greens,  grays, 
browns,  and  reds.  Likewise,  when  attempting  to  match  a 
green,  he  makes  equally  glaring  errors.  As  an  engineer  or 
pilot  he  would  make  serious  blunders  in  reading  red  and 
green  signal-lights.  This,  of  course,  suggests  the  necessity 
of  color  tests  for  all  who  seek  to  enter  such  occupations. 
Figure  61  shows  the  color  zones  of  a  subject  who  is  red- 
green  blind  in  the  right  eye,  with  restricted  color-vision  in 
the  left  eye.  (Notice  that  the  red  and  green  zones  of  the 
right  eye  are  practically  absent.)  Cases  of  yellow-blue  blind- 
ness are  very  rare.  The  cases  that  have  been  reported  are 
pathological  and  not  congenital,  as  are  most  of  the  cases  of 
red-green  blindness. 


I go  PSYCHOLOGY 

Total  color-blindness  is,  in  nearly  every  case,  congenital. 
The  totally  color-blind  see  all  colors  as  different  intensities 
of  gray.  They,  therefore,  live  in  a  colorless  world.  The 
spectrum  appears  as  a  band  of  grays,  lighter  in  the  centre 
and  shading  off  into  darker  grays  toward  both  ends.  The, 
totally  color-blind  eye  is  a  dark-adapted  eye;  the  maxi- 
mum brightness  of  the  spectrum  is,  for  all  illuminations,  in 
the  region  of  the  green,  and  the  fovea  is  in  some  cases  perma- 
nently blind,  so  that  an  object  in  the  outer  world  cannot  be 
fixated  directly.  This  is  the  reason  why  totally  color-blind 
persons  jerk  and  twitch  the  eyes  about  (nystagmus)  in  their 
attempts  to  see  clearly.  It  is  probable  that  the  total  color.- 
hlinH  vision  is  rod -vision.  Although  usually  inherited  and 
congenital,  in  some  cases  color-blindness  has  been  acquired 
either  by  the  prolonged  action  of  colored  lights  upon  the 
retina,  or  through  the  use  of  drugs  (nicotin,  santonin) ,  or  by 
certain  diseases  of  the  retina.  In  its  acquired  form  it  may 
sometimes  be  limited  to  certain  definite  portions  of  the  retina, 
leaving  the  rest  of  the  retinal  areas  normal. 

Persons  with  normal  color-vision  do  not  all  possess  the 
same  sensitivity  for  colors.  Some  show  what  has  been 
called  "anomalous"  color- vision.  They  are  not  really  color- 
blind, but  their  color-vision  is  disturbed.  While  they  can 
see  all  the  colors,  they  do  not  match  them  as  the  perfectly 
normal  person  does,  indicating  that  the  colors  are  not  ex- 
actly the  same  in  quality  for  them. 

Color  Theories. — We  have  already  seen  that  the  differ- 
ence between  colorless  and  color  vision  is  explained  by  the 
theory  that  the  former  is  the  faction  of  the  i$ds,  while  the 
latter  is  attributed  to  the  ccujerof  the  retina.  But  we  have 
made  no  attempt  to  explain  how  the  eye  makes  the  further 
distinction  of  color-vision.  What  is  the  basis  for  the  four 
elementary  color-sensations?  Are  there  four  kinds  of  cones, 
one  kind  for  red,  one  for  yellow,  one  for  green,  and  one  for 
blue,  each  sensitive  to  light- waves  of  a  certain  length  only? 
Such  a  theory  is  evidently  too  simple  to  explain  the  facts  of 


VISUAL   SENSATIONS  19  1 

color-vision.  For  example,  how  could  we  then  explain  the 
fact  that  certain  colors,  when  mixed,  produce  colorless,  while 
others  give  intermediate  color  sensations?  Yellow  and  blue 
give  gray,  while  yellow  and  red  give  orange.  Furthermore, 
why  does  adaptation  to  yellow  increase  the  sensitivity  to 
blue  and  not  to  red  ?  These  and  other  facts  show  that  the 
relation  between  the  four  elementary  color-sensations  is  not 
uniform.  A  color  theory  must  be  able  to  explain  all  the 
facts  of  adaptation,  complementary  colors,  after-images,  color 
mixtures,  contrasts,  and  color-blindness.  While  a  number  of 
theories  of  color-vision  have  been  proposed,  no  one  has 
absolutely  met  this  requirement. 

The  Young-Helmholtz  Theory.  —  This  theory,  first  pro- 
posed by  Young  and  later  modified  by  Helmholtz,  is  based 
upon  the  assumption  that  there  are  only  three  elementary 
colors  —  carmine  red,  slightly  yellowjshgreen,  and  ultrama- 
rine blue.  It  is  supposed,  according  to  this  theory,  that 
there  are  three  photochemical  substances  in  the  retina,  which 
correspond  to  these  color-sensations.  The  red  substance 
is  chiefly  affected  by  the  longer  waves  (recPway_es)  ;  the 
green  substance  by  the  medium  waves  (green  waves),  and 
the  blue  substance  py  me  shorter  waves  (blue  waves)  of 
the  spectrum!  All  the  color-sensations,  together  with  white, 
are  the  result  of  the  activity  of  these  three  retinal  substances. 
Each  substance  is  supposed  to  be  affected  somewhat  by  any 
light-stimulus,  but  chiefly  by  its  own  appropriate  stimulus. 
Thus,  while  red  light  has  its  greatest  effect  upon  the  red 
substance,  it  also  affects  the  other  substances  slightly.  Equal 
excitation  of  all  three  substances  gives  the  sensation  of  white. 
Any  color  would  then  have  some  white  light  (brightness)  in 
it.  This  would  account  for  the  fact  tV|  p^Wc  Qrf*  npy/»r 


satiiraierLqr   P"re-     Black   is    the   absence   of  .  * 
stimulation.     Complementary  after-images  are  due  to  fatigue 
of  the  photochemical  substance  stimulated.     The  other  sub- 
stances, then  being  fresh,  react  more  powerfully  to  a  gray 
stimulus,    giving    the    complementary    after-image.     Color- 


PSYCHOLOGY 

blindness  is  due  to  the  absence  of  one  or  more  of  the  sub- 
stances in  the  retina. 

There  are  several  serious  objections  to  the  theory:  If 
white  is  the  compound  of  all  three  colors,  then  in  partial 
color-blindness,  where  one  color  is  supposed  to  be  absent, 
the  sensation  of  white  would  be  impossible.  This  is  con- 
trary to  fact,  for  in  cases  of  partial  color-blindness  in  one 
eye  only,  white  appears  the  same  to  both  eyes.  Moreover, 
in  total  color-blindness,  sensations  of  white  are  still  possible, 
although  all  the  components  of  white,  according  to  the 
theory,  are  absent.  The  fact  that  a  mixture  of  green  and 
blue  gives  a  sensation  (blue-green)  like  both  components, 
while  a  mixture  of  green  and  red  gives  a  sensation  (yellowish 
gray)  totally  unlike  either  component  color,  is  not  satisfac- 
torily explained  by  the  theory.  In  fact,  the  most  serious 
|j  defect  in  the  theory  sterns  t™  lip  in  that  it  does  not  recognize 
//  yellow  as__an_elementary  color,  but  considers  it  as  a  compound 
jj  of  red  and  green.  In  the  intermediate  zone  of  the  retina  and 
irTred^green  blindness,  color-vision  is  yellow-blue  vision.  In 
these  cases  yellow  cannot  be  compounded  from  red  and 
green,  since  they  are  absent.  Furthermore,  yellow  and  blue 
are  complementary  colors  here,  as  well  as  in  normal  and  cen- 
tral vision.  It  would  therefore  seem  that  yellow  is  as  ele- 
mentary as  blue,  or  red,  or  green,  making  four  instead  of 
three  elementary  colors. 

Hering  Theory. — The  Hering  theory  recognizes  four  ele- 
mentary color-sensations,  red,  yellow,  green,  and  blue,  and  two 
elementary  colorless  sensations,  white  and  black.  They  exist 
in  three  pairs,  the  members  of  each  pair  standing  in  opposite 
or  complementary  relation  to  each  other.  The  pairs  are 
red  and  green,  yellow  and  blue,  and  white  and  black.  For 
each  pair  of  sensations  it  is  assumed  that  there  is  a  single 
photochemical  substance  whicn  has  two  antagonistic  chemi- 
cal processes — a  dissimilative  and  an  assimilative  process. 
There  are  then  threevteoal  substances  in  thV  retina:  a  red- 
green  substance,  a  yellow-blue  substance,  ancl  a  white-black 


VISUAL   SENSATIONS 


193 


substance.  Red^yjellow,  and  white  light  Jjreak  down  or 
cause  dissimilation,  while  green,  blue,  and  black  light  build 
up  or  cause  assimilation  in  these  three  substances  respectively. 
For  instance,  red  light  breaks  down  the  red-green  substance 
and  green  light  builds  it  up.  After  the  dissimilative  effect 
of  red  light,  the  red-green  substance  tends  to  recover  equilib- 
rium, i.  e.,  assimilation  sets  in.  This  explains  the  green 
after-effect  of  red  stimulation.  Any  color-stimulus  not  only 
acts  upon  its  own  substance,  but  also  acts  upon  the  white- 
black  substance.  This  explains  why  all  colors  possess  bright- 
ness. In  case  complementary  colors  (for  instance,  yellow 
and  blue)  act  equally  upon  the  yellow-blue  substance  at  the 
same  time,  they  neutralize  each  other,  but,  since  they  affect 
the  white-black  substance  also,  the  result  is  a  sensation  of 
gray.  If,  however,  these  colors  affect  the  white-black  sub- 
stance in  equal  but  opposite  ways,  the  retinal  substances 
would  all  be  in  equilibrium,  and  the  gray  which  results  is 
supposed  to  be  a  cortical  gray  (a  neutral  or  middle  gray), 
which  originates  in  the  brain  centre  and  corresponds  to  the 
absence  of  retinal  activity.  This  neutral  gray  is  supposed 
to  be  constantly  present  in  vision  and  to  mix  with  all  visual 
sensations.  Only  when  the  given  complementary  colors 
affect  the  white-black  substance  in  different  directions  un- 
equally, or  both  affect  it  in  the  same  direction,  so  that  either 
assimilation  or  dissimilation  takes  place,  is  the  resulting  gray 
(light  gray  or  dark  gray),  a  retinal  gray.  The  color  zones  of 
the  retina  are  supposed  to  be  determined  by  the  presence  or 
absence  of  the  different  substances.  The  cones  of  the  inner- 
most zone  contain  all  three  substances,  those  of  the  inter- 
mediate zone  only  the  yellow-blue  and  the  white-black  sub- 
stances, while  those  of  the  outermost  zone  contain  only  the 
white-black  substance.  Contrasts  are  due  to  the  fact  that  \ 
any  direct  action  of  a  stimulus  on  a  part  of  the  retina  setsy 
up  a  process  of  opposition  in  the  parts  not  stimulated. 

We  may  object  to  the  Hering  theory  on  the  ground  that 
one-half  of  all  the  light  and  color  sensations  must  be  due, 


194  PSYCHOLOGY 

according  to  the  theory,  to  an  assimilative  process  in  the 
substance  of  the  sensory  end-organs.  This  opposes  our  ordi- 
nary conception  of  the  effect  of  stimulation.  Furthermore, 
the  conception  of  the  so-called  "cortical  gray"  makes  an 
exception  to  the  general  rule  that  all  sensory  experiences 
originate  in  sense-organ  stimulation.  According  to  the 
theory,  however,  the  conception  of  the  cortical  gray  is  neces- 
sary. For,  if  the  white-black  substance  is  antagonistic,  as 
the  other  substances  are,  in  its  activities,  then  when  both 
white  and  black  stimulate  it  equally,  the  result  must  be  no 
sensation  at  all.  But,  since  in  fact  we  get  gray  under  these 
circumstances,  the  theory  was  forced  to  assume  that  it  is 
a  cortical  and  not  a  retinal  gray. 

Ladd-Franklin  Theory. — Mrs.  Ladd-Franklin  has  proposed 
a  genetic  color  theory,  which  assumes  that  our  present  color 
vision  is  a  development  from  a  primitive  stage  of  colorless 
vision.  Such  a  condition  now  exists  in  the  outermost  zone 
of  the  retina,  but  the  central  portion  of  the  retina  has  devel- 
oped away  from  its  original  state,  and  now  is  able  to  produce 
color-sensations.  The  theory  assumes  a  single  photochemi- 
cal substance  in  both  the  rods  and  cones.  But  in  the  rods 
it  exists  in  its  original,  undifferentiated  form,  in  which  any 
light-stimulus  whatsoever  acts  upon  the  molecule  as  a  whole, 
"breaking  it  down  in  all  its  parts  and  giving  the  sensation  of 
gray.  In  some  of  the  cones  the  elements  of  the  molecule 
have  been  differentiated  into  two  parts,  such  that  one  part 
is  affected  only  by  the  longer  waves  of  the  spectrum  and 
gives  the  sensation  of  yellow,  while  the  other  part  is  affected 
by  the  shorter  waves  and  gives  the  sensation  of  blue.  These 
cones  are  found  in  the  intermediate  zone  of  the  retina.  In 
the  other  cones,  found  only  in  the  innermost  zone,  the  yellow 
compound  has  been  further  differentiated  into  two  groupings, 
such  that  red  light  affects  one  and  green  light  the  other. 
The  three  stages  of  development  may  be  represented  as 
shown  in  Fig.  62. 

In  the  first  stage  the  photochemical  substance  acts  as  a 


VISUAL   SENSATIONS 


195 


whole.  In  the  second  stage  the  two  parts  may  act  sepa- 
rately. In  the  third  stage  the  three  parts  may  act  separately. 
According  to  the  theory,  complete  decomposition  of  the 


w 


1st  Stage 


2nd  Stage 


W 


G 


3rd  Stage  ( 


W 


"\ 


FIG.  62. — Scheme  to  illustrate  the  Ladd-Franklin  theory  of  color-vision. 
After  Ladd-Franklin. 

photochemical  substance  gives  sensations  of  gray  or  white. 
Partial  decomposition  gives  color.  Thus,  if  both  yellow  and 
blue  light  act  upon  the  yellow-blue  cones,  the  result  is  the 
original  sensation  of  colorless  light,  since  both  stimuli,  when 
acting  together,  break  down  the  molecules  completely.  If 
green  and  red  act  upon  the  green-red-blue  cones,  they  arouse 


196  PSYCHOLOGY 

the  sensation  of  yellow,  but  if  green,  red,  and  blue  all  act 
upon  these  cones,  the  original  sensation  of  white  or  gray  is 
aroused.  If  any  color-stimulus  acts  alone,  the  molecules  are 
only  partially  affected,  and  so  produce  sensations  of  color. 
One  of  the  advantages  of  this  theory  is  that  it  provides  a 
common  basis  for  peripheral  gray,  gray  of  very  faint  light, 
and  the  gray  produced  by  mixing  colors. 

Many  other  theories  have  been  proposed,  but  the  theories 
mentioned  are  the  representative  theories,  and  they  serve 
to  show  us  the  nature  and  the  difficulties  of  the  problem  of 
color- vision. 


* 


CHAPTER  IX 
PERCEPTION 

Perception  of  Objects.  —  We  have  seen  that  sensation  is 
the  consciousness  of  the  qualities  of  objects.  Perception,  on 
the  other  hand,  is  the  consciousness  of  objects,  the  result  of 
the  presentation  of  a  group  of  physical  qualities  to  the  senses. 
For  instance,  we  do  not  say  that  we  have  the  sensation  of 
the  rose,  but  rather  that  we  perceive  the  rose.  We  may 
sense  its  simple  qualities  one  by  one,  but  when  color,  form, 
tactual  qualities,  and  fragrance  are  experienced  all  at  the  * 

same  time,  we  are  aware  of  an  object.     The  perception  of  a    Isf* 
rose  is  not,  however,  the  sensation  of  color  plus  the  sensation    '  jr 
of  form,  plus  the  sensation  of  fragrance,  etc.,  it  is  a  unitary  j>r 
experience  —  an  experience  of  a  single  object  and  not  of  a 
group  of  separate  qualities. 

We  may  consider  sensation  as  the  awareness  of  the  quali- 
ties of  an  object,  while  perception  is  the  consciousness  of  the 
qualities  of  an  object  synthesized  into  an  object.  Insensa- 
tion,  whatjwe  experiencejs  determined_by  the_sdmulus.  "  (5n 
the  other  hand,  in  perception  we  supplement  and  interpret 
the  presented  stimuli  by  past  experiences.  We  are  conscious 
of  more  than  the  group  of  sensations  given  by  the  stimuli. 
Past  experiences  are  awakened  and  are  synthesized  into  the 
percept.  Perception  is  the  consciousness  of  sense-impressions 
interpreted  in  terms  of  past  experiences.  In  the  perception 
of  a  book  we  are  not  only  conscious  of  what  the  senses  give, 
but  of  much  more  —  its  closed  pages,  printed  words,  chapters, 
cuts,  etc.,  which  are  not  presented  to  the  sense-organs.  My 
perception  of  apple  includes  the  consciousness  of  it  as  a  solid, 
as  having  a  white,  juicy  pulp,  arid  as  having  another  side 
which  is  turned  away  from  me.  Here  we  have  reinstatements 

197 


198 


PSYCHOLOGY 


of  past  experiences  with  books  and  apples  entering  into  the 
present  percept.  If  we  have  had  no  past  experience  with 
books  and  apples,  another  group  of  revived  images  may  sup- 
plement the  sense-impression  when  these  objects  are  pre- 
sented to  us.  We  might  then  perceive  the  book  as  a  flat 
box  and  the  apple  as  an  imperfect  ball.  A  little  girl  from 
the  tenement  quarters  who  had  never  seen  ferns  of  any  kind 
called  a  large,  flowing  fern  "a  pot  of  green  feathers."  If  an 
object  which  is  entirely  unlike  anything  we  have  known  is 
sented  to  us,  it  will  be  experienced  as  a  mass  of  sensation, 
aving  no  significance  for  us — a  bare  sensory  consciousness. 
Such  a  state  of  consciousness  rarely  occurs,  however,  for  it 
is  difficult  to  find  an  object  wholly  unique  and  not  in  some 
way  related  to  past  experience.  Our  simplest  awareness  of 
objects  is  supplemented  by  the  modifications  of  past  experi- 
ences. Sometimes,  however,  the  amount  of  supplementation 
is  very  small.  To  one  listening  to  the  spoken  words  of  an 
unfamiliar  language,  the  words  appear  as  a  series  of  meaning- 
less sounds — naked  sensations,  so  to  speak.  No  supplemen- 
tation from  past  experience  takes  place,  and  consequently 
perception  reduces  to  mere  sensations  of  sound. 

More  often  than  we  think  is  the  consciousness  of  objects 
supplied  out  of  our  own  minds.  I  perceive  the  angles  of  the 
rectangular  table  in  front  of  me  as  right  angles,  although  the 
sensory  stimuli  form  two  acute  and  two  obtuse  angles  for 
the  position  from  which  I  view  the  table  top.  I  perceive  the 
angles  as  right  angles,  because  I  know  from  past  experience 
that  they  are  right  angles.  The  sensations  which  I  receive 
from  the  table  are  modified  by  the  knowledge  gained  from 
past  experience.  How  past  experiences  become  assimilated 
into  our  perceptions  is  illustrated  by  the  following  incident: 
As  I  stood  at  the  window  one  morning,  my  gaze  fell  upon 
the  back  yard  of  a  familiar  house  some  distance  away.  I  was 
surprised  to  see  that  the  yard,  usually  well  kept,  was  filled 
with  broken  limestone.  Wondering  why  the  owner  could  so 
encumber  his  premises,  I  turned  back  to  my  work.  When  I 


PERCEPTION  199 

looked  up  some  moments  later,  I  saw  that  the  broken,  white 
limestone  was  only  the  weekly  wash  hanging  out  to  dry.  I 
then  remembered  that  just  before  looking  at  the  yard  in  the 
first  instance  my  attention  had  rested  for  a  moment  upon 
the  unusually  white  limestone  foundation  of  a  house  that 
was  being  built  near  by.  The  perception  of  the  limestone 
foundation  left  its  impress  upon  the  mind  to  such  a  degree 
that  the  perception  of  the  white  linen  was  completely 
changed.1 

The  student  will  find  in  his  own  daily  life  abundant  illus- 
trations of  the  fact  that  what  we  perceive  depends  not  only 
upon  the  stimuli  affecting  the  senses,  but  also  upon  what  we 
have  perceived  in  the  past.  "Perception  is  not,  as  it  seems, 
the  mere  entrance  of  a  group  of  sensations,  but  an  arousal  of 
old  experiences  by  a  few  newly  entering  sensations."  2 

This  arousal  of  old  experiences  by  incoming  sensations 
has  been  popularly  termed  apperception,  the  usual  meaning 
of  the  term  being  the  process  by  which  the  "raw"  material 
supplied  by  the  senses  is  interpreted  in  terms  of  the  knowl- 
edge already  in  the  mind.  But  owing  to  the  fact  that  the 
term  has  had  various  different  meanings  and  is  now  used 
very  loosely,  a  better  term  to  apply  to  this  process  is  assimi- 
lation. The  sensory  material  which  enters  into  perception  is. 
~we^say,  assimilated  by  past  experiences.  We  use  the  term 
assimilation~to  indicate  the  fact  that  perception  is  "actual 

1  Several  years  ago  I  was  very  much  annoyed  for  several  weeks  by  the 
explosions  of  dynamite,  which  was  being  used  to  blast  out  the  rock  for  a  sewer 
on  the  avenue  in  front  of  the  University.  A  year  after  the  work  was  com- 
pleted I  was  startled  one  day  by  hearing  an  explosion  of  dynamite  directly  in 
front  of  the  University  building.  I  immediately  went  to  the  window  to  see 
if  the  work  had  recommenced  on  the  sewer  line,  but  I  was  unable  to  locate  any 
workmen  on  the  street.  It  was  empty.  Within  the  next  half-hour  I  distinctly 
heard  several  explosions.  I  was,  however,  unable  to  account  for  them  until 
I  discovered  that  the  sounds  that  I  had  perceived  as  explosions  came  from  a 
French  casement  window  which  had  been  opening  and  closing  in  the  wind. 
The  sensations  of  sound  made  by  the  slamming  window  had  aroused  the  expe- 
riences of  a  year  ago.  So  the  interpretation  of  the  sensation  was  determined 
by  the  former  experiences. 

2Pillsbury:  "Attention."  p.  128. 


200  PSYCHOLOGY 

sensations  modified  and  supplemented  by  past  experiences." 
Past  experiences  play  an  important  part  in  determining  the 
character  of  presentations.  They  appear  in  our  new  experi- 
ences in  various  forms:  vague  images  of  previous  sensations, 
motor  tendencies,  implicit  judgments,  meaning,  and  experi- 
ences of  familiarity  and  recognition,  any  one  of  which  may 
at  times  be  scarcely  raised  above  the  threshold  of  conscious- 
ness, and  may  require  very  careful  observation  to  detect 
its  presence  in  perception.  While  past  experiences  are  not 
always  overtly  present  in  the  total  process  of  perception,  the 
nature  of  the  percept  oftentime  shows  that  they  have  been 
determining  elements  in  it. 

There  are,  then,  two  important  phases  in  the  process  of 
perception:  (i)  The  reception  of  sensory  impressions,  and  (2) 
the  interpretation  of  these  impressions  through  past  experi- 
ences already  in  the  mind.  In  every-day  experience  it  is 
usually  impossible  to  separate  these  phases  from  each  other. 
The  total  conscious  reaction  to  an  object  is  immediately  com- 
^bined  into  a  single  experience.  Sometimes,  however,  the 
process  of  assimilation,  or  interpretation,  is  retarded.  The 
sudden  presentation  of  an  unfamiliar  object  may  be  followed 
y  several  attempts  to  perceive  it  correctly.  In  each  the 
attempted  assimilation  takes  different  directions,  using  now 
one  group  of  past  experiences  and  now  another.  The  stimu- 
lus may  be  followed  by  an  appreciable  interval  in  which  no 
assimilation  takes  place.  We  are  unable  for  the  moment  to 
interpret  the  sensations;  then  we  "come  to"  and  recognize 
the  stimulus  as  some  definite  object.  If  by  means  of  the 
tachistoscope,  we  expose  to  view  a  complex  but  familiar  ob- 
ject for  a  few  thousandths  of  a  second,  the  period  is  too  short 
to  permit  of  a  completed  perception.  The  observer  may  get 
a  group  of  sensations,  but  he  is  unable  to  organize  them  into 
the  experience  of  an  object.  If  the  exposures  are  repeated, 
assimilation  gradually  takes  place  and  finally  the  object  is 
correctly  perceived. 

Brain  pathology  furnishes  evidence  of  the  existence  of 


PERCEPTION  201 

these  two  phases  of  perception.  Cases  of  asynibolia  have 
been  recorded,  where  because  of  a  certain  brain  lesion,  pa- 
tients are  unable  to  recognize  familiar  objects,  although  they 
are  able  to  see  them  plainly.  They  receive  the  sensations, 
but  they  are  not  assimilated  by  past  experiences.  Other 
brain  lesions  may  result  in  alexia,  or  inability  to^read.  The 
words  may  be  seen  but  not  understood.  Still  another  form 
of  brain  lesion  may  be  followed  by  worcf,  deafnes^  or  loss  of  the 
ability  to  recognize  the  meaning  of  spoken  word&,  altlwugk 
the  ability  to  hear  the  spoken  words  is  not  interfered  with. 
It  would  seem  in  these  cases  that  the  action  of  higher  units 
of  brain  centres  involving  assimilation  is  cut  off  from  the 
sense  centres  by  the  diseased  condition  of  the  cortex. 

ConsideredJILneural  terms,  then,  the  basis  of  the  procgss  W**^*1 
of  assimilation  consists  in  cortical  modifications  left  ^behind 
by_the  previous  neural  processes,  by  virtue  of_which  certain 
brain  tracts  are  more  perviousjx)  stimuli  than  others^  If  by 
reason  of  past  experiences  a  given  brain  tract  (.4)  is  more 
susceptible  or  more  permeable  to  a  given  set  of  stimuli  than 
another  brain  tract  (B),  the  activity  in  the  sense  centres  will 
be  drained  off  by  (^4),  thus  giving  the  perception  correspond- 
ing to  the  neural  activity  in  (/I).  If  we  may  suppose  that 
there  are  perception  levels  in  the  cortex  (i.  e.,  that  perception 
involves  the  activity  of  higher  or,  at  least,  larger  areas  than 
those  involved  in  simple  sensation),  they  may  be  considered 
as  figured  with  neural  patterns,  corresponding  to  the  different 
objects  experienced.  We  may  presume  that  each  particular 
class  of  objects  leaves  a  definite  system  of  modifications  or 
object-patterns1  in  these  levels.  If  such  a  supposition  de- 
scribes anything  like  the  real  neural  conditions  in  perception, 
then  we  may  conclude  that  every  group  of  stimuli  (*.  e.,  every 
object)  first  arouses  activity  in  the  appropriate  sense  centres. 
The  activity  is  then  drained  off  into  the  particular  cortical 

1  By  "nhjprt  pnttFrPg"  wf>  mean  only  that  the  effect  of  the  experience  of 
an  object  makes  the  neural  structure  more  liable  to  act  again  in  the  same  way 
when  stimulations  from  like  objects  arouse  it  to  activity. 


202 


PSYCHOLOGY 


v.s. 


tracts,  or  object  patterns,  which  have  been  made  permeable 
by  past  experiences,  and  which  retain  the  modifications  made 
by  them.  In  this  way  past  experiences  are  revived  and  in 

turn  modify  or  supplement  the 
sensations. 

The  diagram  (Fig.  63)  will 
make  the  matter  clear  with- 
out attempting  to  go  into  the 
details  of  the  anatomical  and 
physiological  facts  concerned. 
It  is  probably  not  too 
much  to  say  that  all  our 
higher  conscious  experiences 
develop  out  of  our  experiences 
of  objects  (perception).  We 
were  first  introduced  to  a 
world  of  objects  to  which  we 
had  to  react.  Our  first  organ- 
ized and  unified  experiences 
were  therefore  with  objects. 
In  order  to  react  to  them  in- 
telligently, it  became  neces- 
sary to  know  when  an  object 
was  presented,  not  only  what 
its  presented  characteristics 
were,  but  also  to  know  in- 
stantly those  that  were  not 
presented.  This  is  possible 
only  by  the  awakening  of  past  experience  with  the  object. 

It  was  natural,  then,  for  the  various  forms  of  conscious- 
ness to  arise  around  the  object,  and  to  become  amalgamated 

1  It  is  evident  that  the  presence  of  the  process  of  assimilation  makes  per- 
ception a  very  complex  conscious  experience.  The  description  of  perception 
would  be  clearer  if  we  had  denned  it  as  merely  the  reception  and  synthesis 
of  a  group  of  actual  sensations  into  a  unified  experience  corresponding  to  an 
object.  Supplementation  of  the  actual  sensations  by  revived  sensations  could 
then  be  considered  in  the  chapter  on  imagination,  recognition  of  the  sensations 


¥10.63. — V.S. — Visual  stimuli  (back 
yard) ;  V.C. — visual  centre  in  cor- 
tex. 

A  and  B,  higher  cortical  areas;  A,  area  in- 
volved in  perception  of  yard  filled  with 
washing;  B,  area  involved  in  perception 
of  yard  filled  with  limestone;  M1,  modi- 
fications left  by  past  experiences  with 
white  clothes;  M,  modifications  made  by 
recent  experiences  of  white  limestone 
foundation.  If  V.C.  arouses  M ,  then  B 
becomes  active,  and  the  resulting  percep- 
tion will  be  "yard  filled  with  limestone." 
If  V.C.  arouses  M1,  then  A  becomes  ac- 
tive and  the  resulting  perception  will  be 
"yard  filled  with  the  week's  washing." 
The  "limestone"  modification  became 
dominant  in  the  first  perception  because 
the  experience  of  the  stone  foundation 
left  certain  areas  temporarily  more  per- 
meable than  others.1 


PERCEPTION  203 

or  synthesized  into  a  single  efficient  act  of  consciousness. 
We  shall  expect,  therefore,  to  find  in  perception  the  begin- 
nings of  imagination,  judgment  (recognition  is  a  primitive 
form  of  judgment),  and  the  concept  (presence  of  meaning). 

All  three  forms  of  consciousness  are  present  in  the  process 
of  assimilation,  which  involves  three  important  products  of 
past  experience: 

1.  Revived  sensory  experiences. 

2.  Recognition. 

3.  Meaning. 

We  have  already  seen  that  the  consciousness  of  an  object 
contains  sensory  elements  which  are  revived  from  past  ex- 
perience. In  normal  perception,  the  revived  sensations  are  in 
keeping  with  the  actual  sensations  received,  and  true  to  the 
sensible  qualities  of  the  object.  If,  however,  we  happen  to 

l-|p   artnal   gpngafinng  hy  fl    flrnup  of  revived  SCn- 


sations  wjn'^-  arp  ro<:  true  to  the  object,  the  conscious  result 
is  .an  illusion.  Usually  in  normal  perception  the  proportional 
amount  of  actual  sensation  is  large  and  the  amount  of  revived 
sensation  small.  If,  as  may  happen  in  rare  cases  under 
abnormal  conditions,  a  set  of  revived  sensations  is  _, pre- 
sented with  no  accompaniment  of  actual  sensations,  but  pos- 
sessing the  vividness  of  actual  sensations,  the  conscious  re- 
sult is  a  hallucination. 

Complication. — Complication  is  the  term  which  we  apply 
to^  the  process  in  which  an  actual  sensation  of  one  of  the 
qualities  of  an  object  brings  up  the  otherjjualities  with  jt. 
For  instance,  after  my  first  experiences  with  ice,  when  I  sense 
its  coldness,  its  smoothness,  its  transparency,  and  its  weight, 
I  may,  upon  merely  seeing  a  block  of  ice  at  a  distance,  be 
conscious  of  its  coldness,  its  smoothness,  and  its  heaviness 

awakened  by  an  object  would  be  treated  under  memory,  and  the  fact  that 
any  presented  object  aroused  meaning  (signified  something  beyond  itself) 
would  be  treated  under  the  concept.  But  no  object  is  ever  experienced  with- 
out awakening  past  experiences  and  recognitions.  The  synthesis  of  the  past 
and  the  present  is  quite  as  fundamental  in  perception  as  the  synthesis  of  the 
different  actual  sensations  into  a  unity. 


204 


PSYCHOLOGY 


without  touching  it.  Instances  of  complication  are  very 
common.  I  may  hear  the  note  of  a  bird  and  the  other  sensa- 
tions are  revived  into  the  perception.  I  may  hear  a  bell  and 
perceive  a  street-car,  smell  a  pleasing  odor  and  perceive  a 
rose. 

Recognition. — Recognition  is  a  primitive  form  of  judg- 
ment. Judgment,  we  shall  see  later,  is  the  consciousness  .of 
some  relationship  existing  between  things.  In  its  developed 
form  the  consciousness  of  relationship  is  explicitly  experi- 
enced.  Interception,  recognition  is  irnplirij;  When  a  fa- 
miliar object  is  brought  to  our  noticeytve  experience  the  rela- 
tionship of  the  object  now  sensibly  present  to  the  same  ob- 
ject or  to  similar  objects  as  experienced  in  the  past.  When, 
for  instance,  we  perceive  a  book,  we  instantly  feel  that  it  is 
familiar,  that  it  is  something  that  we  have  seen  before. 
While  we  may  not  consciously  represent  to  ourselves  the 
related  parts  in  the  experience,  yet  it  is  nevertheless  an  ele- 
mentary form  of  judgment.  We  implicitly  feel  the  relation 
of  the  present  group  of  sensations  to  our  past  experience  with 

:ooks. 

Meaning. — A  pure  sensation  has  no  meaning.     It  suggests 

othing   beyond    itself.     Pure    sensation    is  the    immediate 

Bareness  of  a  stimulus,  before  further  knowledge  is  aroused. 

erception,  on  the  other  hand,  arouses  further  knowledge. 
Every  object  is  presented  to  us  with  a  background  attaching 
to  it.  The  background  is  the  object's  history,  its  associates, 
its  functions,  etc.,  so  far  as  we  have  known  them.  The  ob- 
,  when  presented,  points  out,  signifies,  suggests  this  back- 
ground to  us — in  short,  has  meaning  for  us.  The  first 
meanings  which  nb|prfo  had  for  us  were  actions.  An  ob- 
ject was  a  thing  to  be  reacted  to  in  a  certain  way — a  bottle 
eant  to-put-in-mouth,  ball  meant  to  roll,  knife  meant  to 
cut. 

The  context  or  background  which  an  object  suggests  may 
be  very  limited  or  very  extended,  according  as  our  experi- 
ence with  it  is  small  or  large.  As  we  become  familiar  with  it 


it  gathers  meanings  which  are  packed  away  in  our  perception 
of  it.  Now  the  thought  or  image  of  an  ohjprf;  rarrying  wjjji 
it  all_the_object's  meanings,  is  a  concept:i  The  sensible  pres- 
entation of  the  object,  if  it  awakens  a  maximum  of  meaning;, 
may  function  as  a  concept.  If  the  emphasis  in  consciousness^ 
is_pjaced  on  the  meaning  rather  than  on  the  sensible  qualities 
ofan  object,  the  perception  is  conceptual  in  its  na^uj-e.  In 
so  far,  therefore,  as  perception  involves  meaning,  it  partakes 
of  the  quality  of  the  concept.  From  the  genetic  point_of[( 
\i  viewA  perception  is  the  beginning  of  conceptual  conscious^  l) 
(jnsss,.  Ih  tKe  earlier  stages  of  perception,  ^epresence  of  the  ') 
U  object  awakened  only  consciousness  of  its  sensible  qualities 
and  faint  glimmerings  of  its  meanings.  Later,  the  object 
may  come  to  be  a  mere  symbol  to  which  we  attach  a.  large 
number  of  jneanings.  When  we  say  that  an  object  is  signifi- 
cant^ it  is  plairTtnat  we  are  not  interested  in  the  object  itself, 
but  in  the  things  that  it  suggests — its  meanings.  In  a  still 
later  development,  the  name  of  the  object  may  serve  instead 
of  the  object  to  arouse  consciousness  of  its  meaning.  When  i 
perception  becomes  so  highly  symbolic,  the  sensible  qualities 
of  objects  form  a  small,  if  any,  part  of  the  content  of  con- 1 
sciousness.  But  perception  does  not  always  develop  into 
concepts.  We  are  obliged  to  react  in  a  practical  way  to  the 
objects  about  us  and  we  must  therefore  take  note  of  their 
sensible  qualities.  Much  of  our  mental  life  remains  on  the 
perceptual  plane — consciousness  of  objects. 

lie  function  of  perr.epiinn.  consists  in  supplying  a  knowl-  // 
u    ol  the  proximate  environment  of  things,  and  thereby  in-//  /**"**?' 
stigating  movements  of  bodily  adaptations.     It  is  evident' y 
that  if  we  were  unaware  of  the  presence  and  nature  of  the 
objects  in  our  surroundings,  we  could  not  survive.       Not 
only  presentsensory  Consciousness  oi  jhe_character  of  the 
ob j ect,  but  also  past  experiences^^  the  Abject J*£p_gg£jn  Per- 
ception and  play  a  part  in  the  control  pf  movement.     We 
may  note  in  passing  that  perception  of  objects  is  most  com- 
plete in  just  those  features  which  call  out  our  practical  reac- 


PSYCHOLOGY 

tions.  The  objects  that  we  handle  and  touch  and  work  with 
produce  in  us  the  clearest  perceptions. 

The  truth  or  falsity  of  any  given  perception  is  determined 
by  further  experience  with  the  object  perceived.  If,  on  ex- 
amination, the  object  fulfils  all  its  functions  and  character- 
istics''^? 1  know  them,  then  I  consider  my  initial  perception 
true;  but  if  it  fails  to  do  this,  I  am  forced_to  correct  my  per- 
ception  of  it.  There  is  one  other  court  of  appeal:  If  other 
persons  perceive  the  object  as  I  do,  i.  e.,  react  to  it  in  the 
same  way  that  I  do,  I  have  a  practical  proof  of  the  truth  of 
my  perception.  If  the  white  powder  which  looks  like  sugar 
tastes  sweet  and  dissolves  in  my  tea,  and  all  the  other  persons 
at  the  table  put  it  in  their  tea,  I  am  practically  sure  that  my 
first  perception  of  it  as  sugar  is  true.  But  if  it  has  a  saline 
taste  or  if  others  put  it  on  meat  and  potatoes,  I  must  con- 
sider my  first  perception  false. 

Illusions. — If  a  group  of  sensory  qualities  of  an  object 
is  supplemented  by  revived  sensations  that  have  no  actual 
basis  in  the  object,  the  perception  is  illusory.  Illusions  are 
due  to  the  fact  that  we  interpret  artnal  gpncsfiVmc  in-t^rmc 
of  old  and  habitual  p-gppj-ipruzpg  Illusion  is  really  an  illus- 
tration of  the  orderly,  uniform,  or  lawful  procedure  of  the 
process  of  perception.  If,  for  instance,  I  have  always  per- 
ceived the  sensible  qualities  abcdefg  as  the  object  X,  and 
now  if  adebcfg  is  presented,  I  am  inclined  by  previous  habit 
of  assimilation  to  perceive  it  as  the  same  object  X.  Sully 
gives  the  following  definition  of  illusion : 

"Illusions  depend  upon  the  general  mental  law  that  when 
we  have  to  do  with  the  unfrequent,  the  unimportant  and 
therefore  unattended-to  and  the  exceptional,  we  employ  the 
ordinary  and  the  familiar  and  the  well-known  as  our  stand- 
ard." 

Aristotle's  illusion  strikingly  illustrates  the  force  of  habit 
in  perception.  Cross  the  index  and  middle  fingers  of  the  right 
hand.  Rub  a  pencil  between  the  tips  of  the  fingers.  Two 
pencils  are  perceived.  Better  still,  roll  a  pea  or  some  round 


PERCEPTION 


207 


object  of  about  the  same  size  between  the  tips  of  the  crossed 
fingers.     Two  objects  are  distinctly  perceived,  in  spite  of  the 
fact  that  you  know  that  there  is  only  one.     We  have  formed  j 
the  habit  of  interpreting  two  simultaneous  •  pressure  sensa-\ 
tions  on  two  non-adjacent  parts  of  the  skin  as  coming  from ' 
two  objects.     In  most  cases  it  has  required  two  objects  to 
touch  the  outer  and  the  inner  tips  of  these  fingers  at  the 
same  time.     Now,  when  by  virtue  of  the  unusual  position  of 
the  fingers,  one  object  gives  the  same  sensations,  we  interpret 
the  sensations  in  the  old  way. 

The  reverse  or  opposite  of 
Aristotle's  illusion  may  be  pro- 
duced very  clearly  by  touching 
the  outer  tips  of  the  still  crossed 
fingers  with  two  objects.  One 
object  is  then  perceived. 

A  modification  of  this  illusion 
may  be  produced  by  blindfolding 
a  subject  and  testing  the  surfaces 
of  his  crossed  ringers  for  the  dis- 
crimination, of  distances  between 
the  two  points  of  a  pair  of  com- 
passes. The  shorter  distances  between  the  two  points  are 
uniformly  judged  greater  than  the  longer  distances,  because 
in  the  normal  position  of  the  fingers  the  compass  points  must 
be  farther  apart  in  order  to  stimulate  the  same  pressure 
spots. 

If  the  concave  side  of  a  false  face  is  painted  to  represent  | 
the  features  of  the  human  face  and  set  up  at  a  distance  of  ] 
twenty-five  feet  or  more,  it  will  appear  convex.     Convexity 
is  a  universal  characteristic  of  faces  and  so  we  read  it  into  the  I 
actual  sensations  coming  from  the  concave  false  face. 

Illusions  of  movement  are  very  common.  Seated  in  a 
motionless  railway- train,  we  may  perceive  our  own  train 
moving  forward,  whenever  a  train  on  the  next  track  moves 
in  the  opposite  direction.  In  actual  perceptions  of  our  own 


FIG.  64. — Diagram  showing  posi- 
tion of  fingers:  (A)  Two  objects 
perceived,  (B)  one  object  per- 
ceived. 


2C>8  PSYCHOLOGY 

movement  forward,  other  objects  always  appear  to  move 
backward.  The  railway-car  situation  furnishes  this  condi- 
tion, the  backward  movement  of  objects.  We  consequently 
interpret  it  as  our  own  movement  forward.  The  same  illu- 
sions may  be  experienced  when  we  look  down  steadily  at  the 
water  flowing  under  a  bridge.  Presently  the  bridge  will  ap- 
pear to  be  moving  up  stream,  carrying  us  with  it.  The  illu- 
sion of  levitation  may  be  experienced  during  a  heavy  snow- 
storm, by  gazing  intently  at  the  falling  snowflakes  and  at 
the  same  time  excluding  everything  else  from  the  field  of 
vision.  The  "magic  swing  illusion"  in  amusement  parks  is 
produced  by  revolving  the  entire  room  around  the  swing. 
To  one  sitting  in  the  swing  the  perception  of  movement 
through  a  complete  circle,  over  and  over,  is  very  realistic. 
AU_JJiQse_illusions  are  due  to_our_tendency  to  read  into  a 
groupofactual  sensations  their_usual  accompaniin^nts. 

There  is  a  second  general  cause  of  illusion1  found  in  the 
t  that  a  temporary  bias  or  tendency  may  be  given  to  the 
interpretation  of  sensations  by  the  "set"  of  consciousness  at 
the^mojnent  sensory  stimulation  is  received.  The  mind  may 
be  "full  of  the  thought"  of  an  object  or  may  expect  a  cer- 
tain object  to  appear.  Then  if  the  sensory  stimulation  is  at 

V  ''       all  applicable,  we  are  disposed  to  perceive  that  object,  al- 

. /^  though  it  may  really  be  another  object  that  is  presented.     If 

jf       I  happen  to  be  thinking  intently  about  the  Klondike  gold- 

v         'fields,  the  word  "cold"  heard  in  a  fragment  of  conversation 

<oTin  another  part  of  the  room  may  be  perceived  as  "gold." 

/•J'jr   f  We  are  very  liable  to  overlook  misspelled  words  in  reading, 

jr  because  the  context  prepares  the  mind  for  the  perception  of 
the  words  in  their  correct  forms.  We  may  conclude  that 
illusions  are  caused  either  by  previous  habits  of  interpreta- 
tion, or  by  a  momentary  set  of  the  mind. 

1  James  gives  two  main  causes  of  illusions:  "The  wrong  object  is  perceived 
either  because  (i)  although  not  on  this  occasion  the  real  cause,  it  is  yet  the 
habitual,  inveterate,  or  most  probable  cause  ...  or  because  (2)  the  mind  is 
temporarily  full  of  the  thought  of  that  object.  .  .  ."  "Principles  of  Psy- 
chology," Vol.  II,  p.  86. 


PERCEPTION  20Q 

So  far  we  have  considered  illusions  as  the  result  of  the 
entrance  of  past  experiences  into  the  perception  process. 
Illusions  of  this  kind  have  been  called  "mixecHUusions,"  i.  e., 
revived  past  experiences  and  actual  sensations  are  combined 
or  "mixed"  in  the  perception  of  things.  Such  illusions  are 
to  be  distinguished  from  those  that  are  due  to  the  effect  of 
actual  sensations  upon  each  other,  i.  e.,  illusions  that  are  due 
tq_the_nature  of  peripheral  stimulations!  illusions  of  this" 
kind  are  called  "pure  illusions."  For  instance,  a  square  of 
white  paper  surrounded  by  a  border  of  green  is  perceived 


FIG.  65. — Muller-Lyer  illusion. 

strongly  tinted  with  red.  '(Contrast  effect.)  The  equal  lines, 
a-b  and  b-c  in  the  Muller-Lyer  illusion  are  perceived  as 
unequal. 

In  both  of  these  illusions  the  presence  of  accompanying 
sensations  apparently  not  included  in  the  perception  of  the 
object  is  effective,  nevertheless,  in  modifying  or  falsifying 
the  perception.  The  presence  of  the  green  border  and  the 
oblique  lines  are  instrumental  in  causing  the  illusions.  The 
so-called  "pure  illusions"  are  constant  in  their  appearance, 
always  occurring  under  the  given  conditions.  The  "mixed 
illusions"  are  centrally  aroused  and  variable,  while  the  "pure 
illusions"  are  peripherally  aroused1  and  constant. 

It  is  claimed  that  illusions  are  not  due  to  errors  of  sense, 

1  There  is,  however,  a  difference  of  opinion  concerning  the  cause  of  the  so- 
called  "pure  illusions."  Some  authorities  contend  that  even  in  the  perception 
of  simple  lines,  as  in  the  Muller-Lyer  figure,  suggestions  from  past  experience 
enter  into  the  illusion  and  that,  therefore,  centrally  aroused  factors  play  a  part 
in  the  errors  of  simple  perception.  (See  Ladd  and  Woodworth:  "Elements  of 
Physiological  Psychology,"  pp.  447-453.)  We  can,  at  least,  say  that  in  the 
"pure  illusions"  the  peripheral  factors  are  more  pronounced  than  in  the  "mixed 
illusions." 


210  PSYCHOLOGY 

but  rather  to  our  judgment,  or  interpretation  of  sensations. 
James  says:  "The  so-called  fallacy  of  the  senses  of  which  the 
ancient  sceptics  made  so  much  account,  is  not  a  fallacy  of 
the  senses  proper,  but  rather  of  the  intellect,  which  interprets 
wrongly  what  the  senses  give."1  If  sensation  is  taken  to 
mean  simply  the  conscious  effect  of  stimuli  upon  us  or  within 
us,  without  reference  to  any  existence  in  the  outer  world, 
then  sensation  cannot  be  said  to  be  either  false  or  true.  Con- 
sciousness can  be  false  only  when  it  erroneously  represents 
something  beyond  itself.  An  unprojected  sensation  of  blue, 
for  instance,  cannot  be  false  in  itself.  It  is  just  what  it  is. 
When,  however,  it  is  taken  as  a  quality  of  an  object — a  blue 
paper — then  it  is  false,  if  it  fails  to  represent  the  true  color 
of  the  paper.  The  simpler  the  consciousness  the  less  chance 
for  falsification.  A  single  sense-experience  (when  not  modi- 
fied by  other  experiences)  reports  correctly  the  sensible  qual- 
ity it  Represents. 

Hallucinations. — The  usual  distinction  between  illusions 
and  hallucinations  consists  in  regarding  illusions  as  the  erro- 
neous perception  of  sense-impressions  and  hallucination  as 
perception  without  sense-impressions.  Thus,  if  I  perceive  a 
coat  hung  over  a  chair  as  a  burglar  in  the  room,  the  percep- 
tion is  an  illusion,  but  if  I  see  my  mother  enter  the  room 
when  really  she  is  in  a  distant  city,  the  perception  is  a  hal- 
lucination. Aside  from  the  question  whether  the  distinction 
absolutely  valid  or  not,  itjs  evident  thatjhe  presence  and 
sencej^f  ^sense-stimuli,  is  a  physical  and  not  a  psychological 
difference.  On  the  conscious  side  the  two  experiences  are 
alike  in  that  they  appear  to  report  what  actually  exists  in  the 
objective  world.  So  far  as  the  experience  at  the  moment  is 
concerned,  they  are  not  to  be  differentiated  from  perception. 
While  illusions  are  very  common  occurrences  in  the  normal 
mind,  hallucinations  are  usually  the  product  of  a  very  seri- 
ously  disturbed  or  disordered  mind.  Hallucinations  may  be 
A  symptoms  of  insanity;  they  appear  in  many  cases  of  religious 

l  "Principles  of  Psychology,"  vol.  II,  p.  86. 


PERCEPTION 

ecstasy,  or  in  abnormally  prolonged  devotiorf  to  any  cause; 
they  are  the  result  of  the  use  of  certain  dndgs  or  of  bodily 
disease.  The  visions  of  E^nanuel  SwedenbQrg  were  the 
outcome  of  religious  ecstasy,  and  those  of  Joan  of  Arc  of 
prolonged  devotion  to  a  patriotic  cause.  Continued  intem- 
perance in  the  use  of  alcoholic  drinks  may  produce  the  hal- 
lucinations  of  delirium  tremens,  in  which  the  victim  is  tor- 
men  ted  by  realistic  visTorTS.  Chloroform,  ether,  hashish, 
and  opium  will  also  cause  hallucinations.  A  grewsome  de- 
scription of  opium  hallucinations  may  be  found  in  Thomas 
de  Quincey's  "  Confessions  of  an  English  Opium-Eater."  Hal- 
lucination may  appear  in  hypnotic  states  and  during  diseases 
involving  high  states  of  fever. 

Hallucinations  may  be  experienced  by  persons  in  normal 
health,  but  such  occurrences  are  extremely  rare.  It  is  said 
that  Raphael  had  visions  of  the  Madonna,  following  a  pro- 
longed  attempt  to  image  her  face  in  order  to  paint  it.  Spi- 
nello,  after  painting  "The  Fall  of  Lucifer,"  was  reproached 
by  the  devil  in  person  for  representing  him  in  so  hideous  a 
manner.  * 

The  following  is  a  typical  case  of  hallucination  in  a  nor- 
mal individual:  "I  sat  one  evening  reading,  when,  on  looking 
up  from  my  book,  I  distinctly  saw  a  school-friend  of  mine, 
to  whom  I  was  much  attached,  standing  near  the  door.  I 
was  about  to  exclaim  at  the  strangeness  of  her  visit,  when, 
to  my  horror,  there  were  no  signs  of  any  one  in  the  room  but 
my  mother.  I  related  what  I  had  seen  to  her,  knowing  that 
she  could  not  have  seen  it,  as  she  was  sitting  with  her  back 
to  the  door,  nor  had  she  heard  anything  unusual,  and  she 
was  greatly  amused  at  my  scare,  suggesting  I  had  read  too 
much  or  that  I  had  been  dreaming."1 

Dreams  oftentimes  take  on  the  appearance  of  reality  and 
are,  therefore,  forms  of  hallucinations.  The  appearance  of 
ghosts,  apparitions,  spectres,  etc.,  may  be  pseudo-hallucina- 

1  Quoted  from  the  Proceedings  of  the  Society  for  Psychical  Research,  Collec- 
tion 83,  21. 


-***  «- 


ions,  where  there  is  a  feeling  that  they  are  not  real  exis- 
tences, but  mere  seeming.  They  are  true  hallucinations  in 
cases  where  they  appear  to  be  real. 

Hallucination,  like  perception,  may  involve  'only  one 
sense,  or  several  senses.  Those  of  sight  and  hearing  are 
mmmrm^  while  tactile  hallucinations  are  relatively  in- 
frequent. It  is  rather  difficult  to  determine  whether  an  ol- 
factory or  gustatory  experience,  without  apparent  objective 
stimulation,  is  wholly  subjective,  or  is  due  to  slight  stimuli 
which  we  are  unable  to  detect. 

The  neural  basis  for  hallucinations  and  illusions  is  prob- 
abjy  the  same  as  in  perception.     If,   for  any  reason,   the 
^^neural  pattern,"  or  areas  involved  in  normal  perception, 
become  centrally  stimulated  into  full  and  adequate  activity, 
the  conscious  result  is  the  same  as  in  perception.     Blood 
pressure  in  the  brain  in  fever,  irritation  of  the  neural  tissue 
resulting  from  the  toxic  effect  of  drugs,  or  from  fatigue  fol- 
lowing continued  thought  on  one  subject,  might  be  the  occa-< 
^ion  for  setting  off  definite  "object  patterns"  which  are  the 
neural  basis  for  the  perception  of  objects.     In  this  way,  we 
might  understand  how  Raphael's  continued  thought  of  an 
imaginary  Madonna's  face  might  in   the  end  exhaust  the 
brain  areas  and  break  down  the  normal  inertia  of  the  brain 
cells  and  bring  about  the  same  form  of  neural  activity  as  the 
actual  presence  of  the  object  would  cause.     The  imaginary 
I  form  would  then  be  experienced  as  real.     It  would  seem  that 
I  some  form  of  central  stimulation  must,  in  cases  of  hallucina- 
tion, reach  either  a  sufficient  degree  of  intensity,  or  quality, 
I  to  set  off  the  same  brain  centres  and  the  same  kind  of  neural 
j  action  which  is  required  in  perception  and  which  is  initiated 
normally  by  sense-stimulation. 

PERCEPTION  OF  SPACE    (S(f  ^^  ^^ 

The  phrase  "perception  of  space"  is,  in  a  way,  mislead- 
ing.    We  do  not  perceive  a  denniteunitary  thing  which  we 
:grmtnmr  that  mflyjhr      "But,  rather,  we  perceive 


PERCEPTION  213 


things   or  objects   which   have   spare   rp.la.tiVm  a   fr>   parh    nffrgr 

and  to  us  as  perceiving  beings.  We  perceive  objects  in  cer- 
tain positions,  directions,  and  distances.  We  speak,  how- 
ever, of  the  consciousness  of  these  spatial  relations  as  the 
perception  of  space  (more  properly,  the  perception  of  spaces). 
Although  the  consciousness  of  space  seems  very  simple,  it  is  ^ 
nevertheless  a  very  complex  experience,  and  one  of  the  most 
difficult  of  all  our  experiences  to  analyze. 

The  first  question  to  appear  is:    Is  the  consciousness  of 
space^native,  or  is  it  acquired?    Do  we  sense  space  directly 
as  we  sense  color,  odor,  taste,  pressure,  and  sound,  or  is  space 
experience  the  result  of  combining  sensations  into  percep- 
tions?   There  are  two  opposing  theories  concerning  it.     (i)  -     -7 
The  nativistjg  theory  holds  that  we  possess  a  native  and  u 
direct  consciousness  of  space  prior  to  all  experience,  just  as 
we  possess  the  consciousness  of  the  simple  qualities  of  ob- 
jects —  color,    sound,    etc.     (2)    The    empiristic,    or    genetic 
theory,  on  the  other  hand,  holds  that  we  have  no  simple  or 
direct  experience  of  space,  that  space  experiences  are  wholly, 
acquired,  and  that  they  are  the  result  of  the  synthesis  or» 
combination  of  different  sensations.     According  to  this  theory  ' 
the  development  of  space  experiences  out  of  the  synthesis  of 
sensations,  which  in  themselves  possess  no  space  experience, 
is  briefly  as  follows:    In  the  main  the  sensations  which  com- 
bine to  form  space  experience  arg^visual^  tactile,,  and^movej-  /V.  £  . 
ment  sensations.     They  combine  in  various  ways.     To  take 
a  single  case  from  pressure-sensations  and  movement-sensa- 
tion^: We  may  suppose  that  every  point  on  the  skin,  from 
tKePvery  first,  gives,  when  stimulated,  a  slightly  different 
pressure-sensation  from  every  other  point.     This  difference  A 
is  called  "lQ£aJ^sigJi-"     The  differences  are  not  space  differ- 
ences; they  are  merely  qualitative  differences.     If  two  points, 
A  and  B,  four  inches  apart  on  the  forearm,  are  similarly 
stimulated,  the  experience  given  would  be  that  of  two  differ- 
ent pressure  qualities,  local  signs  A1  and  Bl.     But  now,  sup- 
pose that  the  other  hand  moves  from  point  A  to  point  B. 


214  PSYCHOLOGY 

Then  sensation  of  the  movement  from  A  to  B  would  be  in- 
terposed between  the  consciousness  of  local  sign  A1  and  local 
sign  B1.  The  two  different  pressure-sensations  and  the  move- 
ment-sensation would  fuse  into  the  unitary  perception  of 
the  space  distance  A-B.  Eye  movements  may  also  inter- 
vene between  the  points  A  and  B.  A  synthesis  of  the  sensa- 

»\tion  of  a  certain  amount  of  eye  movement  and  the  two  differ- 

\ient  pressure-sensations  would  then  give  the  perception  of  the 
]pistance.4-J3.  The  theory  also  assumes  systems  of  local  sign 
differences  on  the  surface  of  the  retina  and  in  joint  surfaces. 
From  the  perception  of  distance  to  the  perception  of  surfaces 
and  the  perception  of  the  third  dimension  is  a  further  devel- 
opment, based  chiefly  upon  the  sensations  of  movement  and 

ytocal  sign  differences  in  articular  sensations.1 

j^"  James2  stands  for  a  modification  of  the  nativistic  theory. 
He  holds  that  there  is  a  kind  of  native  bigness  or  "volumi- 
npusness,"  which  he  calls  "extensity,"  observable  hi  all  sen- 


ti,  and  that  this  is  an  attribute  of  all  sensations,  just  as 
j    \?  j^Tntensity  is  an  attribute.     "We  call  the  reverberations  of  a 

/^\r  /thunderstorm  more  voluminous  than  the  squeaking  of  a 
/  slate  pencil;  a  little  neuralgic  pain,  fine  as  a  cobweb,  in  the 
face,  seems  less  extensive  than  the  heavy  soreness  of  a  boil, 
or  the  vast  discomfort  of  a  colic  or  a  lumbago."  This  "volu- 
minousness,"  or  "crude  extensity,"  is  the  native  experience 
from  which  space  perception  develops.  Otherwise  Professor 
James's  point  of  view  is  thoroughly  genetic.  Voluminous- 
ness,  or  extensity,  possesses  no  spatial  order.  It  is  not  di- 
vided and  subdivided  into  parts,  as  our  developed  space 
world  is.  The  ordering  of  this  primitive  space  is  the  result 
of  experience,  and,  as  in  the  genetic  theory,  local  sign  differ- 
ences play  an  important  part  in  bringing  it  about. 

The  author  agrees  with  those  who  follow  an  intermediate 

1  For  a  more  complete  statement  of  the  empirical  theory  of  space  percep- 
tion, the  student  is  referred  to  Wundt's  "Outlines  of  Psychology,"  third  edi- 
tion, p.  113. 

z  "Principles  of  Psychology,"  vol.  II,  p.  134. 


PERCEPTION  215 

theory  between  the  empiristic  and  nativistic  points  of  view. 
Some  of  our  sensations  do  give  an  immediate  "outspread," 
or  "alongsidedness,"  of  sensory  qualities  which  is  a  crude 
spatial  awareness.  On  the  other  hand,  the  definite  space 
world,  as  we  now  know  it,  is  the  result  of  experience  and 
development.  Through  various  combinations  of  sensations 
which  synthesize  with  the  vague  experience  of  "spreadout- 
ness,"  we  come  to  have  definite  perceptions  of  position,  direc- 
tion, and  distance. 

The  senses  which  furnish  the  original  material  for  space 
perception  are  the  visual  and  the  cutaneous.  Light-stimuli 
act  simultaneously  upon  a  large  number  of  nerve-endings  on 
the  retina  and  arouse  an  immediate  experience  of  "spread- 
outness."  Pressure-stimuli  upon  the  surface  of  the  skin  like-  / 
wise  affect  a  large  number  of  pressure  spots  simultaneously  I 
and  set  up  sensations  which,  although  alike,  are  sufficiently  I 
different  to  be  distinguished.  To  these  senses,  therefore, 
objects  seem  to  have  a  number  of  simultaneously  existing 
parts1  which  stand  outside  of  each  other.  The  definition  and 
the  order  of  the  parts  are  not  immediately  given  by  sensa- 
tion^but  come  as  the  result  of  further  pxperienre.  If,  for 
instance,  when  the  eyes  are  closed,  a  pair  of  compass  points, 
i  mm.  apart,  are  placed  upon  the  skin  of  the  forearm,  we 
perceive,  not  two  distinct  points,  but  a  small  expanse  cf 
pressure.  If  we  separate  the  compass  points  gradually,  a 
certain  space  interval  will  be  reached  where  they  will  be  felt 
as  two  points.  They  will  not,  however,  be  perceived  as  hav- 
ing a  definite  direction  or  distance  from  each  other.  One 
cannot  say  that  one  point  is  to  the  right  or  to  the  left  of  the 
other.  There  is  merely  the  experience  of  the  points  as  out- 
side or  alongside  of  each  other — a  vague  experience  of  primi- 
tive space. 

The  olfactory,  gustatory,  and  auditory  senses  do  not,  in 

'The  use  of  the  word  "part"  seems  to  beg  the  question.  The  term  does 
not,  however,  refer  to  definable  spatial  units,  but  only  to  the  crude  extension 
which  we  hold  is  natively  given  in  the  retinal  and  skin  sensations. 


2l6  PSYCHOLOGY 

any  tangible  way,  report  objects  as  being  "spread  out"  or 
having  "alongsidedness,"  and  so  the  sensations  coming  from 
them  do  not  possess  the  attribute  of  extension.  For  instance, 
in  auditory  sensations,  a  number  of  different  sounds  fuse 
together  and  the  resulting  experience  is  not  given  as  made 
up  of  parts  existing  alongside  each  other.  A  sound-stimulus 
does  not  act  upon  a  number  of  discriminable  different  sense 
surfaces.  Therefore,  the  sound  is  not  experienced  as  having 
spatial  parts  or  extension.  It  should  be  stated  in  this  con- 
nection that  some  psychologists  claim  that  sound-sensations 
do  possess  a  native  "voluminousness,"  spatial  in  its  charac- 
ter, as,  the  quotation  from  James,  on  a  preceding  page,  testi- 
fies. However,  this  spatial  character  is  not  developed.  A 
sound  never  comes  to  have,  in  our  highest  development  of 
space  perception,  one  part  of  it  spatially  set  off  against  an- 
other part.  We  are  never  able  to  distinguish,  say,  an  upper 
right-hand  corner  of  a  sound.  Sensations  of  taste  and  smell, 
likewise,  do  not  develop  into  distinct  spatial  arrangements. 

Development  of  Space  Perception.  —  It  is  evident,  when 
we  inquire  into  the  development  of  space  perception,  that 
there  are  two  phases  in  the  breaking  up  of  vague  space  ex- 
,-periences  into  perceptions  of  the  definite  order  and  the  ar- 
rangement  of  parts  which  the  world  of  objects  shows,     (i) 
ocalization  —  the  ordering  of  the  different  parts  of  the  skin 
sun  ace  with  reference  to  each  other,  so  that  we  are  able  to 
localize  pressure-sensations  more  or  less   definitely  on   the 
/  ...  various  parts  of  the  skin  surfaces.     (2)  Projection  —  the  pro- 

1      *o^    jection  of  sensory  qualities  to  definite  Brails  of  a  space  world 
'>*r        beyond  the  body.     These  two  processes  go  on  at  the  same 

^  time  and  are~reciprocally  helpful  to  each  other.     We  may 

compare  the  size  of  certain  objects  seen  with  the  size  when 
superimposed  upon  the  skin.  Or  a  seen  area  of  the  skin  may 
be  compared  with  the  same  area  as  felt. 

How  do  we  come  to  perceive  definite  positions,  directions, 
and  distances  upon  the  skin  surface,  since  they  are  not  given 
natively?  As  we  have  indicated,  it  takes  place  through  the 


,-^ 
^jf:  ra 


PERCEPTION  217 

synthesis  of  different  sensations.  The  perception  of  the  dis-, 
tance  between  two  points  on  the  skin  is  the  synthesis  of  the) 
sensation  of  the  movement  required  to  trace  the  distance' 
between  them  with  the  finger  or  with  the  eyes,  and  the  pres-} 
sure-sensations  themselves.  By  moving  the  hand  over  the 
skin  surface,  we  trace  lines  of  directions  and  set  up  a  series 
of  differing  pressure-sensations  which  combine  with  the  sen- 
sations of  movements  made  in  tracing  the  lines.  At  the 
same  time  the  eyes  may  follow  the  movement,  and  the  sen- 
sations arising  therefrom  may  also  enter  into  the  perception 
of  the  distance  on  the  skin.  Likewise,  the  articular  sensa- 
tions, arising  from  the  slipping  of  the  joint  surfaces  over  each 
other  may  form  a  part  of  the  perception.  Localization  (or  | 
perception  of  directions  and  distances)  is  most  refined  and 
accurate  on  the  more  mobile  parts  of  the  skin  surfaces,  and 
most  crude  and  inaccurate  where  few  tracing  movements 
have  been  made,  e.  g.,  on  the  back.  The  perception  of  dis- 
tance between  two  points  on  the  skin  corresponds  to  the 
number  of  discernible  different  pressure-sensations  that  may 
be  aroused  between  the  points.  For  instance,  a  distance  on  A'* 
the  finger-tip  of  4  mm.  seems  much  greater  than  it  does  on 
the  back  of  the  hand,  because  the  local  differences  in  pressure 
are  greater  in  number  in  a  given  area  on  the  finger-tip  than 
on  the  back  of  the  hand. 

In  the  same  way,  distances  and  directions  are  determined 
in  the  outer  world  by  movement  of  hand  and  eye  over  parts 
of  objects  exterior  to  the  body.  The  greater  the  intensity  of 
the  movement  required  to  trace  the  contours  and  distances 
between  points,  the  greater  the  perceived  space  magnitude. 
Eye  movements  arouse  a  series  of  retinal  sensations  which 
are  combined  with  the  movement-sensations  in  the  percep- 
tion of  magnitude.  If,  for  instance,  we  fixate  a  point  A  on 
the  wall  directly  in  front  and  then  turn  the  eyes  to  the  right 
through  an  angle  of  30°  to  the  point  B,  point  A  will  trace 
corresponding  lines  on  the  right  halves  of  the  retinze,  i.  e.,  the 
image  of  point  A  will  move  from  the  central  position  on 


2l8  PSYCHOLOGY 

each  retina  to  the  right.  The  perception  of  the  distance  and 
the  direction  is  formed  out  of  the  series  of  the  retinal  sensa- 
tions and  the  movement-sensations,  which  are  interposed 
between  the  terminal  retinal  sensations. 

The  original  space,  given  by  the  eyes,  is  a  vague,  formless 
expanse,  without  definite  directions  or  distances  in  it.  But, 
as  the  sensations  of  movements  of  eye  and  hand,  in  trac- 
ing distances  and  directions,  combine  with  the  sensations 
aroused  on  the  retina,  the  objects  in  the  outer  world  take  on 
form  and  show  a  definite,  spatial  relationship  to  each  other. 
Cutaneous  space  and  visual  space  are  compared  and  harmo- 
nized by  the  fact  that  the  same  series  of  movement-sensations 
(movements  of  small  extent)  may  measure  both  spaces,  i.  e., 
movements  may  trace  distances  felt  and  distances  seen. 

Third  Dimension. — Movement  again  plays  an  important 
part  in  the  perception  of  the  third  dimension.  The  hand 
may  move  in  all  directions — up  and  down,  right  and  left,  to 
and  from  the  body.  For  instance,  if  the  hand  moves  from 
the  face  to  an  object  a  short  distance  away,  the  cutaneous 
sensations,  caused  by  the  contact  of  the  hand  with  the  face 
and  with  the  object,  have  interposed  between  them  a  series 
of  articular  and  movement  sensations,  which  may  be  com- 
bined into  a  perception  of  depth.  The  articular  and  move- 
ment sensations  acquire  a  space  value  in  tracing  surface  mag- 
nitudes on  the  skin.  Or  the  hand  may  fold  upon  itself,  giving 
a  series  of  articular  sensations,  interposed  between  the  cuta- 
neous sensations  of  the  hand  open  and  the  hand  closed.  The 
articular  sensations  themselves  may  combine  with  move- 
ment-sensations, just  as  cutaneous  sensations  do,  into  a  per- 
ception of  distance,  so  that  a  movement  of  the  arm  may  be 
perceived  as  having  a  definite  space  magnitude.  This  is  pos- 
sible because  of  the  fact  that  the  articular  sensations  possess 
an  original  spatial  character,  which  becomes  ordered  into 
definite  space  perceptions  through  combinations  with  sensa- 
tions of  muscular  tension. 

Whether  the  sense  of  vision  can  give  an  original  experi- 


PERCEPTION  219 

ence  of  the  third  dimension  or  not  is  a  question  which  has 
been  much  discussed  in  psychology,  since  the  time  of  Berke- 
ley.1 He  thought  that  the  visual  estimate  of  the  third  di- 
mension is  "an  act  of  judgment,  grounded  on  experience, 
rather  than  of  sense,"  for,  he  said,  "distance  being  a  line 
directly  endwise  to  the  eye,  it  projects  only  one  point  on  the 
fund  of  the  eye,  which  point  remains  invariably  the  same, 
whether  the  distance  be  longer  or  shorter."  Berkeley  called 
attention  to  the  fact  that,  in  judging  distance  in  the  third 
dimension,  we  converge  the  eyes  more  for  nearer  objects  than 
for  the  farther  objects.  The  degree  of  convergence  gives  rise 
to  eye-movement  sensations,  which  act  as  cues  to  the  judg- 
ment of  distance. 

Berkeley  was  right  in  asserting  that  the  perception  of  the 
third  dimension  is  not  a  simple  sense  experience,  but  a  very 
complex  experience,  into  which  sensory  factors  from  both 
eyes  enter.  In  the  first  place,  visual  perception  involves  two 
retinal  images  of  every  object  perceiveoL  If  the  images  fall 
upon  corresponding  parts  of  the  retinae,  the  object  is  per- 
ceived as  single;  if  they  fall  upon  non-corresponding  parts,Jt_ 
is  seen  as  doubly.  The  fixation  of  an  object  brings  the  two 
images  upon  corresponding  areas  of  the  retinae,  while  images 
of  objects  nearer  and  farther  away  than  the  fixation-point 
fall  upon  non-corresponding  areas.  The  result  is  that  objects 
fixated  are  seen  single,  while  objects  which  are  nearer  and 
farther  away  than  the  object  fixated  are  seen  double,  if  they 
are  attended  to  sharply. 

Hold  up  a  pencil  in  front  of  the  eyes,  with  the  blunt  end 
nearer  and  about  eight  inches  distant,  and  the  sharpened 
end  pointing  directly  away  from  the  eyes.  (The  experiment 
will  succeed  more  readily  if  the  pencil  is  held  by  means  of  a 
pin,  inserted  at  its  middle  point.)  Fixate  the  nearer  end  and 
two  pencils  are  seen,  joining  at  the  point  fixated.  Fixate  the 
farther  end  and  two  pencils  are  seen,  joining  at  their  farther 

'Berkeley:  "Essay  Toward  a  New  Theory  of  Vision,"  1709.     For  discus- 
sion, see  James:  "Principles  of  Psychology,"  vol.  II,  p.  212. 


22O 


PSYCHOLOGY 


ends,  the  right  pencil  extending  toward  the  right  eye  and  the 
left  pencil  toward  the  left  eye.  Fixate  the  middle  point  of 
the  pencil  and  the  two  pencils  are  seen  crossing  each  other 
•  at  that  point.  Now,  look  at  the  pencil  without  attempting 
to  fixate  any  one  point.  It  appears  as  a  single  object. 

It  is  evident  that  when  the  pencil  is 
seen  as  a  single  object  the  two  disparate 
images  fuse,  so  that  the  result  is  a  single 
percept,  but  a  percept  which  includes  the 
experience  of  the  object  as  solid  (third 
dimension).  Careful  observation  will 
show  that,  as  the  fixation-point  changes, 
the  disparate  images  fuse  at  the  point  of 
fixation.  In  the  normal  perception  of 
objects  the  eyes  are  constantly  moving 
over  them,  now  fixating  one  point  and 
now  another.  These  different  views  are 
synthesized  into  a  single  percept,  includ- 
ing the  muscular  sensations  of  conver- 
gence and  divergence,  which  act  as  a  cue 
to  the  distances  from  the  eyes  to  the 
different  parts  of  the  object. 

The  ordinary  stereoscope  produces   a 
marked  perception  of  the  third  dimension 
by  causing  two  flat  but  disparate  views  of 
the  same  object  to  fall  upon  correspond- 
ing parts  of  the  retinae.     The  stereoscope, 
therefore,  brings  about   artificially   the  natural  eye   condi- 
tions, which  are  present  in  the  normal  perceptions  of  objects 
having   the    third    dimension.     The    stereoscope  views   are 
taken  with  a  double  camera,  so  arranged  that  two  views 
of  an  object  or  scene  are  taken — one  corresponding  to  the 
view  that  the  right  eye  gets  of  the  object  and  one  corre- 
sponding to  the  view  that  the  left  eye  gets  of  it.     When 
they  are  placed  in  the  stereoscope,  the  right  view  is  pre- 
sented to  the  right  eye  and  the  left  view  to   the  left  eye. 


FIG.  66. — Diagram  to 
show  the  different 
view  of  the  pencil 
for  each  eye.  The 
right  eye  gets  an 
image  of  the  pencil 
on  its  right  side;  the 
left  eye  gets  an  im- 
age of  its  left  side. 
The  images  are  dis- 
parate images. 


PERCEPTION  221 

The  two  views  then  fuse  into  a  single  picture,  possessing 
the  third  dimension.  If  two  pictures  exactly  alike,  i.  e.,  hav- 
ing no  binocular  disparity,  are  placed  in  the  stereoscope,  the 
perception  of  the  third  dimension  does  not  take  place. 

There  are  many  acquired  aids  to  the  perception  of  dis- 
tances in  the  third  dimension,  effective  because  of  past  asso- 
ciations formed  in  our  experience  with  things  at  different  dis- 
tances away  from  us.  Some  of  the  most  important  are: 

Sensations  of  Convergence  and  Accommodation. — Trie 
eyes  converge  more  for  near  objects  than  they  do  for  far 
objects  and  the  lens  of  the  eye  changes  its  curvature  for 
objects  at  different  distances.  The  varying  intensities  of  the 
sensations  arising  from  these  eye  movements  become  asso- 
ciated with  various  distances  and  so  become  suggestions  of 
them.  For  distances  greater  than  one  hundred  feet,  sensa- 
tions of  accommodation  and  convergence  are  of  too  low  a 
degree  of  intensity  to  be  used  as  cues  of  distances. 

Size  of  thejtetinal  Imaee  (linear  perspective} . — The  farther 
away  a  given  object  is  from  the  retina,  the  smaller  the  retinal 
image.  The  changes  in  the  size  of  the  image  are  not  inter- 
preted  as  changes  hi  the  size  of  the  object,  but  rather  as 
changeFm  Qistance~ol  tne  object  irom  the  eyelH  IFweTnow 
thtTsize  oi  an  object,  we  can  judge  its  distance  by  the  size  of 
the  retinal  image. 

As.rjal  Pf.rxpf.rJ.im. — Distinctness  of  outline  of  objects  is 
associated  with  nearness  and  indistinctness  with  distance. 
Also,  distant  objects  show  a  different  color,  due  to  the  effect 
of  the  atmosphere.  The  distant  hills  and  mountain  ranges 
are  tinged  with  purple.  The  green  of  woods  and  field  becomes 
bluish,  as  they  stretch  away  in  the  distance.  In  the  clear 
atmosphere  of  the  mountains  the  distinctness  of  distant  ob- 
jects causes  marked  underestimation  of  these  distances  by 
those  unused  to  such  conditions.  Quite  a  contrary  effect  is 
produced  if  objects  are  seen  through  a  fog  or  a  very  hazy  at- 
mosphere. The  dimming  of  outline  causes  the  objects  to 
appear  unusually  large,  "to  loom  up,"  so  to  speak.  Since 


f  A/0; 

/     i.L.c 


,  ?> 


222  PSYCHOLOGY 

dimness  is  the  sign  of  distance,  the  objects  are  perceived 
as  farther  away  than  they  are.  They  therefore  must  appear 
larger. 

Shadow.  —  Objects  haing  projecting  parts,  or 


objects  in  relief,  show  a  characteristic  distribution  of  light 
and  shadow,  determined  by  the/source  of  light.  More  dis- 
tant parts  are  in  shadow.  Flat  drawings  may  therefore  be 
made  to  suggest  the  third  dimension  by  proper  shading.  A 
cameo  will  appear  as  an  intaglio  if  the  source  of  light  is  be- 
low rather  than  above. 

A  n^ajr  Perspective..  —  The  form  of  a  known  angle  sug- 
gests  the  distance  from  the  eye  to  the  surface  bounded  by  the 
angle.  The  right  angle  of  the  top  of  the  table  changes  its 
apparent  form  as  it  changes  its  distance  from  the  eye.  The 
apparent  form  of  the  angle  is  a  cue  to  its  distance. 

Interposition.  —  Near  objects  cover  or  cut  off  farther  ob- 
\/  jects.     We  perceive  the  porch  column  to  be  nearer  than  the 
part  of  the  house  that  it  cuts  off.     We,  therefore,  perceive 
the  house  as  standing  behind  it. 

/^T\  Parallax.—  If.  the  eyes  are'  fixed  upon  some  object  and  the 
Whead  is  moved  laterally,  say  to  the  right,  nearer  objects  ap- 
pear to  move  to  the  left  and  objects  beyond  the  fixation- 
point  appear  to  move  to  the  right.  If  the  objects  are  very 
near  or  very  far  away,  the  apparent  displacement  is  large. 
If  the  objects  are  nearer  the  fixation-point,  the  displacement 
is  small.  This  parallactic  displacement  becomes  an  indica- 
tion of  'the  relative  distances  of  objects. 

Space  Errors  and  Illusions.  —  We  have  already  referred  to 

the  fact  of  disparity  of  space  perception  between  the  different 

senses,  and  also  in  the  same  sense.     The  cavity  of  a  newly 

extracted  tooth  seems  much  larger  to  the  tip  of  the  tongue 

than  it  does  to  the  finger-tip,  or  to  the  eyes  when  viewed  in 

a  mirror.     If  the  points  of  a  compass,  three-fourths  of  an 

/       inch  apart,  are  pressed  against  the  face,  the  distance  between 

\\them  will  feel  greater,  if  one  point  is  above  and  the  other 

'  Af\     below  tne  mouth,  than  it  does  when  they  touch  the  cheek. 


PERCEPTION 


223 


Filled  space  extent  seems  larger  than  unfilled,  when  both  are 
applied  to  adjacent  parts  of  the  skin  at  the  same  time,  but  if 
the  space  extents  are  applied  successively  to  the  same  area, 
unfilled  space  seems  larger. 

The  student  may  test  the  truth  of  this  statement  with  two 
visiting  cards  of  the  same  length.  Notch  the  edge  of  one 
so  that  it  will  have  saw-teeth  three-eighths  of  an  inch  apart. 
Then  cut  the  other  card  so  that  only  two  teeth  appear,  one 
at  each  extremity.  Close  the  eyes  and  have  someone  press 
the  two  cards  against  adjacent  parts  of  the  skin.  Compare 
their  relative  lengths.  Apply  the  cards  alternately  to  the 
same  area  and  compare  their  apparent  lengths. 

The  larger  number  of  space  illusions  are  visual.    YerJical 

distances  are  perrai'yFd   ^  grpa.tpf  than  pqna.1  horizontal  (iis- 


tances.  Place  two  points  vertically,  one  above  the  other,  on 
a~sheel  of  paper.  Look  steadily  at  the  two  points,  and  then 
locate  a  point  to  the  right  of  the  lower  one,  so  that  it  appears 
to  mark  off  a  distance  equal  to  the  distance  between  the 
vertical  points.  Compare  the  distances.  The  horizontal  dis- 
tance will  appear  to  be  larger.  Compare  the  vertical  and 
horizontal  lines  in  Figure  67.  Which  are  the  longer? 


FIG.  67. 

The  upper  half  of  a  vertical  line  is  overestimated  in  com- 
parison with  the  lower  half.  Divide  a  vertical  line  in  halves 
so  that  the  upper  and  lower  halves  appear  equal.  Measure 


224 


PSYCHOLOGY 


them.  Select  the  letter  "s"  or  the  figure  "  8,"  on  a  page  of 
printed  matter,  and  compare  the  upper  and  the  lower  halves 
of  each,  as  to  their  relative  sizes.  Turn  the  page  upside 
down  and  compare  them. 

Note  the  .following  illusions  and  try  to  explain  them. 


(a)  Zollner  figure. 


(6)  Bering  Figure. 


(c)  Lipps  parallels. 

FIG.  68. — The  lines  in  Zollner's,  Bering's,  and  Lipps's  figures  are  parallel, 
lower  arc  in  the  Muller-Lyer  circle  is  an  extension  of  the  larger  arc. 


The 


PERCEPTION 


225 


(d)  Miiller-Lyer  circle. 


(e)  Poggendorff  figure. 


(/)  Jastrow  illusion  of  area. 

FIG.  68.  (Con.) — In  the  Poggendorff  figure  the  lower  oblique  line  is  an  exten- 
sion of  the  upper  oblique  line.  The  two  areas  in  Jastrow's  illusion  of  area 
are  equal. 


One  of  the  most  interesting  space  illusions  is  the  Miiller- 
Lyer  illusion,  the  typical  form  of  which  is  represented  in 
Figure  69. 

Many  explanations  of  this  illusion  have  been  offered.  It 
has  been  suggested  that  the  overestimation  of  the  left-hand 
line  and  the  underestimation  of  the  right-hand  line  are 
due  to  the  different  eye  movements  induced  when  looking 
at  the  lines.  The  arrow-heads,  enclosing  the  line  on  the 


226  PSYCHOLOGY 

right,  check  eye  movements  before  they  reach  the  extremities 
of  the  lines.  On  the  other  hand,  the  oblique  lines  on  the 
left  side  of  the  figure  lead  the  eye  out  beyond  the  extremities 
of  the  line.  Since  the  amount  of  effort  made  in  tracing  a 


FIG.  69. — Miiller-Lyer  illusion. 


line  will  affect  the  judgment  of  the  length  of  the  line,  the  lef t- 


ime  win  anect  me  judgment  01  me  lengui  01  me  mie,  me  ien- 
hand  line  is  perceived  as  the  longer. 

The  eye-movement  theory  may  be  applied  to  most  of  the 
other  illusions.  It  is  claimed  that  movements  induced  by 
W  \  perpendicular  lines  require  more  effort  than  movements  in- 
duced by  horizontal  lines.  Hence,  perpendicular  lines  seem 
'  longer  than  horizontal  lines  of  the  same  actual  length.  In 
the  Miiller-Lyer  circle,  it  is  supposed,  according  to  the  eye- 
movement  theory,  that  the  eyes,  in  tracing  the  circle,  tend 
to  move  outward  from  the  extremities  of  the  upper  arc  and 
so  pass  below  the  lower  arc,  making  it  appear  too  far  toward 
the  centre  of  the  circle.  Likewise,  Jastrow's  illusion  of  area 
might  be  explained  as  due  to  eye  movement.  The  eye,  in 
passing  over  the  figures,  is  inclined  to  trace  the  proximate 
parts  of  the  figures.  The  two  lines  that  lie  nearest  together 
attract  the  eyes  and  initiate  movements  over  them.  Hence, 
a  shorter  movement  for  the  upper  figure  and  a  longer  move- 
ment for  the  lower  figure  is  the  basis  for  the  judgment  of  the 
areas  of  the  figures. 

Other  theories  also  have  been  proposed  for  these  illusions. 
The  p_ersrjectiye  theory  assumes  that  the  simple  lines  in  these 
drawings  indicate  the  third  dimension.  For  instance,  the 
oblique  lines  in  the  Miiller-Lyer  figure  suggest  (subcon- 
sciously) perspective  distance.  The  oblique  lines,  forming  the 


PERCEPTION  227 

arrow-heads,  appear  nearer  where  they  join  the  horizontal 
lines.  The  oblique  lines,  forming  the  feather-ends  of  the 
figure,  seem  farthest  away  where  they  join  the  horizontal 
line.  Hence,  the  right-hand  line  appears  nearer  and  the 
left-hand  line  farther  away  in  perspective.  The  nearer  right- 
hand  line  must  then  be  judged  shorter  and  the  farther  left- 
hand  line  longer,  since  their  retinal  images  are  of  the  same 
length.  Vertical  lines,  also,  according  to  the  theory,  suggest^ 
the  third  dimension  and  are  seen  in  perspective.  They  are* 
therefore  foreshortened  and  overestimated,  when  compared 
with  horizontal  lines. 

The  dyjiajnk__th£pry  of  Lipps  holds  that  the  ideas  sug- 
gested by  figures  affect  the  perception  of  the  figures.  Thus  a 
slender  spire  suggests  an  upward  force,  which  suggestion  en- 
ters into  the  perception  of  the  spire  itself;  hence,  the  effect  of 
Gothic  architecture.  In  the  Miiller-Lyer  figure  the  right- 
hand  side  of  the  figure  suggests  the  idea  of  being  limited,  re- 
strained, and  cramped,  while  the  left  part  suggests  freedom, 
scope,  and  room  for  movement.  These  ideas  affect  the  per- 
ception. 

The  rnnfiisinn  theory  of  space  illusions  is  based  upon 
our  tendency  to  confuse  a  part  of  a  figure  with  the  whole  of  ^ 
it,  or  upon  our  habit  of  perceiving  figures  as  wholes  or  units 
and  not  as  parts.  Thus,  in  the  Miiller-Lyer  figure,  we  are 
led  by  this  tendency  to  judge  the  distances  between  the 
arrow-heads  as  a  whole,  rather  than  to  judge  the  distance 
between  the  ends  of  the  line,  or  points  of  the  arrow-heads. 

There  are  other  theories  offered  for  the  explanation  of 
space  errors  and  illusions,  but  they  are  modifications  of  those 
just  described.  It  seems  probable  that  no  one  theory  can 
account  for  all  the  illusions.  Some  of  the  illusions  may  be 
due  to  many  different  influences.  Perception,  as  we  have 
seen,  isji  highly  jcompjex  and  synthetic  process.  Past  ex- 


periences and  surrounding  stimuli  may  be  variously  combined 
in  the  perception  of  any  given  object;  hence,  the  many  the- 
ories offered  to  explain  the  falsifications  of  perceptions. 


228 


PSYCHOLOGY 


•f 

<K 


II 


'  S 


The  preceding  theories  of  illusory  space  perceptions  signifi- 
cantly fall  into  two  classes: 

1.  Peripheral  theories,  or  those  which  attempt  to  explain 
space  illusion  as  due  to  simultaneous  sensory  factors.     Such 
is  the  ev.e^mQvement  theory. 

2.  Central  theories,  or  those  which  undertake  to  explain 
illusory  space  perception  upon  the  ground  of  past  experi- 
ences.    Old  habits,  ideas,  and  revived  images  modify  and 

v  contort  the  actual  sensations  aroused  by  line  and  figure. 
^  We  cannot  arbitrarily  decide  between  them.  In  fact,  we 
^  are  inclined  to  believe  that  both  peripheral  and  central  fac- 
^  tors  enter  into  our  perception  of  space.  Especially  so,  since 
in  we  have  found  that  a  large  part  of  space  experiences  is  ac- 
»  quired  upon  the  basis  of  a  very  crude  native  endowment. 
£  Manifold  elements,  both  native  and  acquired,  have  been 
worked  into  our  space  consciousness.  No  one  theory,  there- 
fore, can  account  for  the  various  influences  which  may  be 
brought  to  bear  upon  the  perception  of  objects  in  space. 

Localization   and   Projection    of   Auditory   Sensations. — 
^  Sounds   are   localized   more   or  less  definitely,  both  in  the 
^direction  and  distance  from  which  they  appear  to  rise.     The 
localization  and  projection  of  auditory  sensation  does  not 

•  signify  that  sounds  themselves  possess  the  attribute  of  spa- 
JF^ial  extension,  but  that  they  are  referred  to  certain  positions 

*  in  the  extended  space  world  of  vision,  movement,  and  touch. 

The  accuracy  of  the  localization  of  direction  of  sounds 

£  varies  for  the  different  positions  which  the  sound-stimulus 

>j  occupies  with  reference  to  the  two  ears.     Sounds,  coming 

j  from  any  position  in  the  extended  median  plane  of  the  head, 

^  are  poorly  localized.     One  cannot  tell  whether  the  sound 

j  comes    from   before,   above,   or  behind   the  head.     Sounds 

.,.  which  come  from  positions  outside  of  the  median  plane,  to 

1    the  right  or  the  left  of  the  head,  are  located  fairly  accurately. 

The  explanation  seems  to  lie  in  the  fact  that  the  intensities 

of  a  sound  are  the  same  for  each  ear,  when  the  stimulus  is  in 

the  median  plane.     But  when  the  stimulus  is  outside  the 


PERCEPTION  229 

median  plane,  it  is  nearer  one  ear  than  the  other,  and  so  the 
intensity  of  the  sound  is  greater  for  the  nearer  ear  than  it  is 
for  the  farther  ear.  The  relative  intensities  of  a  sound  in 
the  two  ears  would  seem,  then,  to  be  a  cue  to  the  direction 
of  the  sound. 

This  is  probably  a  sufficient  explanation  for  the  localiza- 
tion of  sounds,  coming  from  near  points.  But  in  case  the 
sound  comes  from  a  distant  point,  the  difference  in  the  dis- 
tances to  the  ears  is  relatively  so  small  that  the  resulting 
intensities  of  the  sound  are  practically  equal  for  the  two 
ears.  The  ability  to  localize  a  distant  sound,  whose  intensities 
are  not  sufficiently  different  to  be  valuable  as  an  indication 
of  direction,  has  not  yet  found  a  satisfactory  explanation. 
More  and  Fry1  suggest  that  the  phase  differences  of  sound- 
waves entering  the  ears  may  serve  as  a  basis  for  distinguish- 
ing the  direction  of  a  sound.  But  this  would  not  account 
for  the  fact  that  persons  deaf  in  one  ear  are  able  to  locate 
the  direction  of  auditory  impressions.  Complex  sounds,  the 
human  voice,  musical  tones  containing  many  partial  tones  are 
located  more  easily  and  accurately  than  simple  tones.  It 
seems  probable  that  the  head  may  cast  sound  shadows,  which 
affect  the  quality  of  a  complex  sound  for  the  ear  on  the  oppo- 
site side  from  its  source.  The  higher  partial  tones  with 
short  wave-lengths  would  be  affected  more  by  the  interven- 
ing head  than  the  lower  tones  with  longer  wave-lengths.  In 
this  case  the  different  qualities  of  complex  sounds  for  the 
two  ears  would  act  as  an  indication  of  direction.  Even  in 
cases  of  persons  deaf  in  one  ear,  the  shape  of  the  shell  of  the 
outer  ear  may  affect  the  quality  of  a  complex  tone,  in  accor- 
dance with  the  direction.  Persons  with  one  ear  only  are  un- 
able to  locate  accurately  pure  or  simple  tones. 

The  distance  from  which  a  complex  sound  comes  to  the 
ear  also  affects  its  quality  or  timbre.  The  weaker  partials 

1  Experiments  made  at  the  University  of  Cincinnati  in  1902,  but  not  pub- 
lished until  1907,  Phil.  Mag.,  April,  1907.  Lord  Rayleigh  was  led  to  the  same 
conclusion  by  somewhat  different  experimental  data.  For  a  more  thorough 
discussion  see  Myers  and  Wilson,  British  Journal  of  Psychology,  1908,  II,  363, 


2JO  PSYCHOLOGY 

become  less  intense  the  greater  the  distance.  They  may  drop 
out  altogether  at  certain  distances.  The  changing  quality 
of  a  complex  sound  may,  then,  be  the  sign  of  its  distance. 
Pure  tones  are  located  with  much  more  difficulty  than  com- 
posite clangs  and  noises. 

Associations  built  up  in  past  experience  also  play  an  im- 
portant part  in  judging  the  distances  of  sounds.  After  we 
have  become  acquainted  with  a  certain  sound,  the  intensity 
with  which  it  reaches  the  ear  is  an  index  of  its  distance. 

PERCEPTION  OF  TIME 

There  is  no  perception  of  pure  time.  The  perception  of 
time  is  involved  in  the  perception  of  objects  which  appear 
to  us  to  have  temporal  continuation  (prolonged  existence). 
Genetically,  the  experience  of  an  object  as  a  continued  exis- 
tence is  derived  from  the  original  and  unanalyzable  experi- 
ence of  sense-impressions,  possessing  temporal  extension. 
Every  sense-impression  begins^  rises  to  its  full  intensity,  and 
then  wanes,  thus  giving  jajtime-span,  which  is  immediately  t 
apprehended" It  is  conceivable  that  even  if  an  object  existed 
onTyTbng^nough  to  give  a  single,  instantaneous  impression 
and  then  disappeared  completely,  it  would  leave  a  time  ex- 
perience because  of  the  rise,  development,  and  waning  phases 
of  the  impression  itself.  Just  as  objects  are  perceived  as 
having  co-existing  and  extended  parts  (spatial  spreadout- 
ness),  they  are  also  perceived  as  having  a  temporal  attribute. 

There  is,  however,  a  difference  of  opinion  among  psychol- 
ogists concerning  the  original  experience  of  time.  We  find, 
as  we  did  in  space  perception,  two  opposing  theories  of  time 
perception.  The  empiricists  hold  that  there  is  no  native 
and  unlearned  time  experience — that  time  perception  is  grad- 
ually acquired  out  of  sense  experiences  that  are  in  themselves 
timeless.  For  instance,  suppose  a  series  of  tactual  sensations 
are  set  up  on  the  back  of  the  hand  by  tapping  it  with  a  pen- 
cil point.  The  tactual  sensations  themselves  cannot,  ac- 
cording to  the  empirical  theory,  give  experience  of  time. 


PERCEPTION  231 

But  there  arises  between  any  two  successive  taps  an  experi- * 
ence  of  expectancy,  a  waiting  for  the  next  tap.     The  intensity  \ 
of  this  expectancy  increases  until  the  arrival  of  the  expected  / 
tap,  when  it  wanes.     So,  between  the  successive  taps,  there 
is  a  gradually  increasing  and  suddenly  ending  expectancy. 
The  fusion  of  these  tactile  and  expectancy  experiences  gives 
the  perception  of  a  time-expanse.     Organic  sensations  (breath- 
ing, muscular  strain,  etc.)  may  also  be  interposed  between 
other  sensations  and  combine  with  them  into  the  perception 
of  time.     In  short,  the  empirical  theory  holds  that  the  mind  1 1 
getstime  out  of  the  combination  oTditterent  sensations,  not  1 1 
tKat^ense  experiences  themselves  give  time  to  the  mind.'       I J 

On  the  other  hand,  the  nativists  hold  that  time  is  an 
original  attribute  of  all  conscious  states — that  it  is  a  part  of 
our  mental  content  from  the  beginning.     The  author  agrees 
with  the  nativists  in  affirming  that  an  original  temporal  attri-  ^f 
bute  attaches  to  all  sensations,  and  with  the  empiricists  in 
maintaining  that  developed  time  perceptions  are  the  result 
of  experience  and  come  about  through  the  synthesis  of  ele-    #r 
mentary  sense  experiences. 

Elements  of  Time  Perception. — The  native  and  primary 
experiences  of  time  are  (i)  simple  duration  and  (2)  succession. 
Simple  duration  arises  out  of  the  fact  already  referred  to, 
that  every  sense-impression  begins,  rises  to  fulness,  and  ends. 
These  phases  are  never  separated — never  given  as  discrete 
parts  of  the  time  interval;  but  they  are  always  bound  together 
in  a  single  moment.  Each  sense-impression  possesses  a  brief  I 
time  breadth — a,  simple  "now" — the  simplest  time  experi-  | 
ences  we  have.  The  content  of  this  simple  moment  is  the 
differing  intensive  phases  through  which  a  sense-impression 
passes  from  its  beginning  to  its  close. 

The  normal  length  of  time  required  for  a  sense-impression,,    [  f i 
to  mature,  or  develop  in  consciousness,  varies  somewhat  within 
the  nature  of  the  stimulus  and  also  with  the  sense  stimulated.'* 
For  ordinary  impression,  it  is  about  one-half  second.     If  a 
series  of  sounds  are  given  one-half  second  apart,  each  sound 


PSYCHOLOGY 

duration  seems  adequate,  but  if  the  sounds  are  nearer  to- 
gether, say  one-fourth  second  apart,  the  duration  of  each  sin- 
gle sound  seems  cramped.  If  the  sounds  are  further  apart 
than  one-half  second,  the  duration  seems  too  long.  In  such 
cases,  there  is  a  tendency  to  fill  in  with  other  sense  material 
— usually  sensations  of  muscular  strain,  respiration,  and 
organic  changes. 

Experiences  of  succession  arise  out  of  our  native  ability 
to  discriminate  between  different  sensory  impressions.  We 
apprehend  a  series  of  sense-impressions  as  a  succession  of 
sensory  "nows." 

By  means  of  the  synthetic  processes  of  perception,  the 
"nows" — the  elements  of  time  experience — are  combined  into 
larger  and  more  complex  units.  Several  sense-impressions 
with  their  simple  durations  may  be  combined  into  a  single 
perception.  For  instance,  I  may  perceive  three  or  more  notes 
on  the  piano,  sounded  in  succession,  as  a  single  time  expanse. 
A  number  of  cutaneous  sensations,  following  each  other,  may 
also  be  perceived  as  a  single  "now."  The  "now,"  in  these 
cases,  is  a  larger  and  more  complex  "now"  than  the  simple 
"nows"  of  sensation.  It  is  the  result  of  the  synthesis  of 
sensory  bits  of  time,  or  simple  durations,  into  a  present  mo- 
ment which  we  call  the  psychical  present. 

The  Psychical  Present. — The  psychical  present1  is  that 
section  of  the  time  expanse  which  we  feel  to  be  presented 
now.  It  varies  in  length  from  about  one-half  second  to  six 
seconds.  Longer  periods  will  not  hold  together,  as  a  unit, 
but  tend  to  break  up  into  component  parts.  The  content  of 
the  psychical  present  is  also  variable.  If  we  listen  to  the 
strokes  of  the  metronome  (120  strokes  a  minute),  it  is  possible 
to  combine  two,  three,  four,  or  six  strokes  into  a  single  per- 
ception. So  with  other  sensory  impressions.  A  varying  num- 
ber of  them  may  be  synthesized  into  the  psychical  present. 

The  number  of  events,  which  we  experience  in  any  present 
moment  is  determined  by  our  adaptive  reactions.  Whatever 

1  Sometimes  termed  the  "specious  present." 


PERCEPTION  233 

corresponds  to  a  single  reaction  is  unified  into  a  present  mo- 
ment.    If  I  count  singly  the  metronome  strokes,  then  each  i 
stroke  occupies  the  present  moment.     If  I  count  them  by/ 
threes,  then  three  strokes  occupy  the  present  moment.     This* 
is  in  harmony  with  the  principle  which  we  found  to  be  true 
in  the  perception  of  objects:  viz.,  that  we  p^rrfivf^  ag  mm-  H 
bined  in  a  single  nhjprf  ty*  grrmp  r.f  CAnsr>ry  impressions _to 
which  we  make  a  single  reaction. 

Sensory  ^Material  of  Time  Perceptions. — While  all  the 
senses  furnish  material  for  time  perception,  the  most  ^promi- 
nent rr>rff»nf  is  fV.^  fi^m'^r]  hy  the  auditory,  kinaesthetic, 
and  tactual  sppctiH'^nc  The  rhythmic  movement  sensations 
in  organic  processes  (breathing  and  heart  action)  may  fill  in 
the  interval  between  two  auditory  or  tactual  sensations  and 
combine  with  them  into  a  single  moment.  As  one  listens  in- 
tently to  the  strokes  of  the  metronome  more  than  a  second 
apart,  the  time  between  them  is  filled  in  and  measured  byi 
sensations  of  respiration  and  muscular  strain  set  up  by  the) 
bodily  attitude  of  listening.  The  duration  of  the  interval  is 
judged  by  the  amount  of  change  in  the  respiratory  and  strain 
sensations.  Genetically,  the  most  original  time  experiences 
are  furnished  by  the  muscular,  tactual,  and  the  organic  sen- 
sations. These  sensations  are  constantly  present  and  fonrTa 
Temporal  continuum  against  which  outer  events  are  pro- 
jected. Events  which  are  perceived  as  taking  place  outside 
ol  the  body  are  measured  bv  the  changes  in  the  bodily  proc- 
esses.  Organic  changes  and  movements  and  pressures  are 
probably  noted  before  the  changes  which  take  place  in  the 
outer  world  (sounds,  lights,  etc.). 

The  Psychical  Present  and  the  Logical  Present. — The 
psychical  present  must  not  be  confused  with  the  present  of 
logical  analysis — the  logical  present.  While  the  former  has 
an  actually  experienced  duration,  the  logical  present  can  be 
shown  to  have  no  duration.  It  is  simply  a  point,  "a  knife 
edge"  dividing  the  past  from  the  future.  Suppose  we  grant 
to  it  a  very  brief  duration,  then  this  duration,  however  short, 


234 


PSYCHOLOGY 


can  be  analyzed  logically  into  a  part  that  has  just  passed 
and  a  part  that  is  yet  to  come  with  the  present  separating 
them.  Any  duration,  whatsoever,  which  is  conceived  to 
belong  to  the  present  may,  therefore,  be  analyzed  into  past 
and  future,  leaving  no  present  duration.  If,  however,  we 
realize  that  the  logical  present  is  theoretical  and  not  an  actu- 
ally experienced  moment  of  time,  it  will  present  no  difficul- 
ties. The  psychological  present  is  an  actually  experienced 
duration.  ffi*X 

The  Past  and  the  Future. — Only  the  present  moment  can 
be  perceived.  The  past  and  the  future  are  mental  construc- 
tions which  we  fill  out  with  imaginary  content.  We  can  thus 
construct  a  time  continuum  extending  in  two  directions 
from  the  actually  perceived  present.  Part  of  the  past,  our 
own,  may  be  represented  in  memory,  but  the  remote  past, 
the  past  of  the  ages,  which  we  contemplate,  is  the  result  of 
constructive  imagination.  The  future  is  also  ideally  con- 
structed. Its  content  is  filled  in  from  the  actually  experi- 
enced events  of  the  past  and  the  present.  Future  events  have 
a  representation  in  the  present  moment  content,  in  so  far  as 
e  represent  them  ideally  and  anticipate  or  await  their  oc- 
currence. But  since  we  can  represent  future  events  only  in 
terms  of  past  events,  the  future  is  conditioned  by  the  past. 
It  has  been  said  that  "the  future  is  not  in  front  of  us,  but 
rolls  up  from  behind  us." 

All  time  is  regarded  as  belonging  to  one  unlimited  time. 
But  we  are  unable  to  form  any  adequate  conception  of  an 
unlimited  time  expanse.  We  cannot,  for  instance,  conceive 
of  a  past  that  stretches  back  without  a  beginning,  or  a  future 
that  has  no  end.  Neither  can  we  conceive  of  a  past  with  a 
beginning,  or  a  future  with  an  end.  Such  attempted  con- 
ceptions, however,  lead  directly  into  the  realm  of  metaphysics. 

The  Measure  of  Time. — For  all  our  practical  purposes, 
we  measure  time  objectively  by  the  regular  movement  of  the 
sun  and  stars.  Clocks  and  watches,  which  divide  time  into 
seconds,  minutes,  hours,  days,  etc.,  mark  off  the  course  of 


235 

the  movements  and  changes  in  the  heavenly  bodies.  Such 
measures  are  purely  objective.  On  the  other  hand,  the  psy- 
chological time,  the  time  which  we  experience  is  subjectively 
measured  by  the  changes  in  consciousness — i.  e.,  by  the  num- 
ber of  sensations  and  ideas  which  occupy  the  attention.  The 
hour  or  day  seems  long  or  short,  according  as  it  is  filled  with 
few  or  many  conscious  changes.  The  so-called  objective 
timeand  the  psychological  time  do  noi 


While  objective  time  has  an  absolute  standard  of  measure  in 
the  physical  happenings  (movements  of  sun  and  stars),  sub- 
jective or  experienced  time  has  no  such  standard.  Of  two 
objectively  equal  periods,  one  may  be  experienced  as  much 
longer  than  the  other.  The  hour  which  seems  short  to  me 
may  seem  very  long  to  my  companion. 

When  deprived  of  any  objective  measure  of  time,  our  esti- 
mation of  the  length  of  intervals  is  based  upon  changes  in 
consciousness  itself.  The  conscious  material,  which  fills  the 
time  intervals,  varies  with  the  length  of  the  interval.  Very 
short  intervals,  less  than  one-half  second,  are  filled  by  the  ^ 
changes  through  which  a  single  sense-impression  passes  as  it 
rises  and  wanes  in  consciousness.  Intervals  from  one-half 
second^  to  four  seconds  are  filled  with  the  muscular  strain  in  ^ 
eve,  ear,  head,  neck,  and  other  parts  of  the  body,  and  inter- 
vals  longer  than  four  seconds  by  the  muscular  sensations  of 
inspiration  and  expiration. 

Short  periods  of  time  (less  than  .75  seconds)  seem  longer  ^ 
than  they  are  objectively,  i.  e.,  they  are  overestimated;  long 
intervals  seem  shorter  than  they  are;  i.  e.,  they  are  under- 
estimated. Between  the  shorter  and  longer  intervals  there 
is  a  duration  which  we  estimate  with  more  accuracy  than  any 
other.  This  is  knnwp  as  the  indifference  period.  Its  abso- 
lute length  is  about  .75  seconds. 

Many  authorities  call  attention  to  the  difference  in  our 
estimation  of  the  length  of  filled  and  empty  time.  There  is, 
however,  no  such  thing  as  empty  time;  for  all  time  intervals 
are  filled  with  some  kind  of  conscious  change.  What  is  meant 


236 


PSYCHOLOGY 


by  empty  time  is  a  time  interval  which  has  in  it  no  clear  sen- 
sations aroused  by  outer  stimuli,  i.  e.,  stimuli  outside  of  the 
body.  Such  intervals  are  really  filled  by  kinaesthetic  and 
organic  sensations  coming  from  bodily  changes.  The  differ- 
ence between  the  so-called  empty  time  and  filled  time  is  the 
difference  between  time  filled  with  sensations  of  bodily  changes 
and  time  filled  with  sensations  of  outer  changes. 

Short  intervals  (less  than  two  seconds)  seem  longer,  when 
filled  with  sensations  of  outer  changes  than  when  empty,  i.  e., 
when  filled  with  kinaesthetic1  and  organic  sensations.  In  judg- 
ing intervals  longer  than  two  seconds  the  estimation  of  their 
length  is  reversed.  Such  intervals,  when  filled  with  interest- 
ing events,  seem  short  when  compared  with  equal  intervals 
not  so  filled.  When  we  are  busily  occupied,  time  flies;  when 
we  are  not  occupied,  time  drags.  An  hour  filled  with  hap- 
penings, activities,  or  ideas  passes  before  we  know  it,  while  an 
hour  with  few  changes  in  it  seems  never-ending. 

The  estimation  of  remembered  time  periods  presents  a 
paradox.  For  time  that  seems  short  in  passing  seem^  long 
whenjwe  review  it  in  mfmf"y;  and  tl'rnp  that  seems  long  in 
passing  seems  short  in  memory.  In  remembering  a  time 
period,  we  estimate  its  length  by  the  number  of  events  that 
have  been  crowded  into  it.  Consequently,  past  intervals  of 
time  that  were  filled  with  events  seem  long,  while  empty  in- 
\  tervals  seem  short  in  retrospect. 

As  we  grow  older  the  time  seems  to  pass  more  quickly 
than  it  does  in  youth.  This  is  especially  true  of  the  longer 
periods  of  time — the  year,  month,  and  week.  To  the  child, 
the  year  seems  much  longer  than  it  does  to  the  adult,  but 
there  probably  is  no  appreciable  difference  in  the  shorter  in- 
tervals—the minute  and  the  second.  The  youth  eagerly 
looks  forward  to  the  future,  impatient  for  all  that  it  holds 
for  him.  The  months  and  years  stand  between  him  and  his 
goal,  and  he  therefore  notes  their  course  more  keenly.  For 

1  When  organic  sensations  become  unusually  intense,  the  time  they  occupy 
appears  longer. 


PERCEPTION  237 

that  reason  the  mature  man,  to  whom  most  of  life's  experi- 
ences have  already  come,  and  who  is  beginning  to  look  back- 
ward as  well  as  forward,  regards  the  passing  time  with  less 
solicitude.  He  is  not  interested,  as  the  youth  is,  in  the  mere 
passing  of  time.  The  mental  attitude  of  waiting,  of  expect- 
ing some  new  experience,  makes  us  aware  of  the  extent  of 
time.  When  the  attention  is  directed  to  the  flow  of  time  II 
itself,  its  seeming  duration  is  lengthened. 


,  MEMORY 

The  Image. — In  sensation  and  perception,  consciousness 
is  awakened  only  when  external  objects  are  presented  to 
the  sense-organs.  We  may,  therefore,  refer  to  sensation 
and  perception  as  presentative  consciousness-— consciousness 
prompted  and  directed  by  external  objects.  But  experiences 
of  objects  which  we  have  once  had  may  be  retained  and  re- 
vived or  re-experienced  again  without  the  presence  of  the 
object  itself,  i.  e.,  we  may  be  conscious  of  objects  not  present 
J;o  the  senses.  I  may  now  have  a  mental  picture  of  an  object 
I  saw  yesterday,  although  the  object  is  not  present. 
Such  consciousness  we  may  call  re-presentative  consciousness 
— consciousness  internally  prompted  and  directed.  The  form 
of  consciousness  in  which  the  sensory  content  of  past  experi- 
ences is  revived  is  known  as  imagination.  In  my  "mind's 
eye"  I  can  see  the  house  I  visited  last  week,  and  hear  the 
voices  of  its  inmates.  These  experiences  are  mental  images. 
MentaUmages  are  conditioned  upon  previous  perceptuaLex- 
perience.  The  person  born  deaf  cannot  have  auditory  images. 
In  short,  without  the  original  sensory  experiences  no  repro- 
ductive consciousness  is  possible.  On  the  other  hand,  any 
actual  sensory  experience  may  be  re-presented  by  means  of 
these  mental  images. 

The  physiological  basis  of  mental  images  rests  (i)  in  the 
retention  of  the  modifications  made  upon  the  brain  by  pre- 
vious experience  and  (2)  in  the  recurrence  of  the  same  or 
similar  nerve  processes  in  the  brain  centres.     The  activity^  of 
"7  1      the  sense-organs.  |ipwp^/pr|  is  riot  rrp>gf>nti      We  may  suppose 
•  *      that  the  neural  process  of  perception  produces  some  modifi- 
cation of  the  nervous  substance  in  the  brain,  and  that  the 

238 


MEMORY  239 

retention  of  this  modification  is  the  condition  for  the  re- 
presentation of  previous  experience.  When  we  speak,  as  we 
often  do,  of  mental  experienct^being  retained  and  reproduced 

basisisalwaysjny^lved. 
~ 


It  is  often  advantageous  to  speakTof  past  experiences  as~stored 
in  the  mind  and  retained  there  until  they  are  again  revived, 
but  this  is  only  a  convenient  fiction  of  scientific  psychology. 
When  we  treat  of  the  association  of  images  and  ideas  we  shall 
continue  to  speak  of  ideas  becoming  associated  together,  and 
of  the  tendency  of  one  idea  to  reproduce  another  by  virtue  of 
the  associative  KmtsT  established  between  them.  However, 
we  take  it  for  granted  that  the  real  link  between  ideas,  and 
between  past  perceptions  and  present  reproduced  images,  is 
the  modifications  retained  in  the  brain  centres. 

There^has  beena  great  deal  of  discussion  as  to  whether 
t&ejmagj|jimi__the^pe^ 

in  different  brain_centres.  The  question  cannot  be  said  to 
be  absolutely~settled,  but  it  seems  very  probable  that  the 
image  and  the  perception  of  an  object  involve  the  same  brain 
centre.  It^is^however,  necessary  to  assume  that  the  nervous 
activities  in  the  ^cortical  ^ntr^cfilTer^^ 
' 


'able  to  disTmglnlsrrl^nir'ISffien^^ 

and  The  image  ot  an  object.     Since  the  conscious  states  are 

alf5terenl,^trie   brain  "processes  which   cause  them   must  be 

different. 

It  is  customary  to  point  out  as  the  difference  between 
perceptions  and  images  the  fact  that  the  former  are  exter- 
nally aroused,  while  the  latter  are  aroused  by  inner  brain 
processes.  'While  this  is  true,  it  is  not  a  difference  in  the 
nature  of  the  experiences  themselves.  However,  the  image 
does  differ  from  perception  psychologically.  Careful  obser- 
vation reveals  the  fact  that  images  are  less  vivid,  less  distinct 
less  stable,  and  \ess_coefcive.  Images  do  no!r  stand  outas 
perceptions  do.  They  are  less  detailed,  more  fragmentary, 
and  more  fickle  or  vacillating  than  perceptions.  Neither  do 
they  hold  or  command  attention  or  move  to  action  as  per- 


240  PSYCHOLOGY 

captions  do.  All  this  is  evident  if  one  will  compare  the 
mental  image  of  a  beautiful  landscape  which  he  has  seen 
with  the  actual  perception  of  a  similar  scene. 

Now,  the  image  is  the  basis  of  two  forms  of  re-presentative 
mental  life  —  memory  and  imagination.  Memory  is  not  only 
a  re-presentation  of  our  past  experiences,  but  it  involves 
recognition  -oLlhgm_as  ^our^owji  Jbrjner  experiences.  Imagi- 
nation, on  the  other  hand,  is  either  (i),  the  mere  revival  of 
sensory  experienjDejwithout^defniite  reference  tojmvjparticu- 
lajTpast  event^  oT^gbjectj  or  (2^, 


events  or  objects  which  have  never  really  taken  place  in  our 
jjwn  experien£e£  TKeTaHeTlsTnTpopular  meaning  of  imagi- 
nation. In  many  cases  past  perceptual  experiences  are  re- 
vived without  any  recognition  of  them  as  actually  having 
been  a  part  of  our  experience.  For  instance,  I  may  be  think- 
ing of  the  currency  bill,  as  pending  in  Congress,  when  a  fairly 
correct  and  definite  mental  image  of  a  silver  dollar  arises  in 
my  mind.  In  this  case  the  image  is  evidently  a  revival  of 
past  perceptions  of  silver  dollars,  but  I  am  not  aware  of  it  as 
such.  Simple  revival  is  known  as  reproductive  imagination. 
Reproductive  imagination  is  an  essential  stage  in  memory. 
Or,  perhaps,  it  would  be  better  to  call  it  the  basis  of  memory. 
However,  it  does  not  constitute  a  complete  memory  act,  as 
we  shall  see. 

/  Definition  of  Memory.  —  Memory  is  the  retention,  recall, 
and  recognition  of  past  experiences.  Since  retention  and 
recall  are  .the  stages  of  reproductive  imagination,  we  may 
say  that  memory  Js^er^oductiy^e^magination  j:)lus  recognj- 
Locke  denned  memory^'  asthe  power  dime  mind  to 


revive  perceptions  which  it  has  once  had,  with  the  additional 
perception  annexed  to  them  that  it  has  had  them  before." 
Practically  the  same  definition  is  given  by  James:  "Memory 
proper  is  the  knowledge  of  an  event  or  fact,  of  which  mean- 
time we  have  not  been  thinking,  with  the  additional  con- 
sciousness that  we  have  thought  or  experienced  it  before." 
But  before  we  can  have  "knowledge  of  an  event  or  fact"  it 


MEMORY  24  f 

must  be  retained  and  recalled.     There  are  then  three  steps  or 
stages  in  a  memory  act : 

1.  Retention. 

2.  Recall. 

3.  Recognition. 

(1)  Retention.    We  have  already  seen  that  the  retention 
of  original  impressions  is  based  upon  the  modifications  made 
upon  brain  tissue,  and  preserved  in  brain  centres.     Some  of 
the  earlier  psychologists   thought  that  mental  impressions 
were  preserved  in  the  "mind"  as  mental  states,  and  that 
therefore  they  were  always  in  existence  "in  the  storehouse  of 
memory"  even  when  we  are  not  conscious  of  them.     There 
is  no  scientific  basis  for  such  a  hypothesis.  ''An  idea  as  a  con- 
scious fact  exists  only  when  the  brain  centres  corresponding  to. 
fc  are  active.7  We  must  therefore  think  of  retention  in  terms 

of  brain  modifications.  Itjs  not  the  mind  but  the  nervous  , ^» 
system  that  retains^>u£^xrjeriences.  Trier eis~c6nsiclerable  dif- 
ference among  individuals  in  ability  to  retain  impressions. 
Some  brains  retain  modifications  made  upon  them  as  wax 
retains  the  impression  of  the  seal,  other  brains  lose  their  modi- 
fications almost  as  soon  as  they  are  made.  Between  these 
two  extremes  lie  many  intermediate  degrees  of  ability  to 
retain  impressions.  The  normal  brain  has  thousands  of  modi- 
fications wrought  upon  its  tissue,  and  these  modifications 
determine  the  nature  of  its  activity.  They  represent  the 
past  experiences  of  the  individual.  Some  of  the  experiences 
have  cut  deep  into  the  tissue,  and  will  never  be  effaced, 
others  have  only  touched  the  surface,  leaving  very  little  trace 
behind  them. 

(2)  Recall.    The  passage  of  a  particular  sensory  impulse 
through  a  brain  centre  leaves  the  centre  capable  of  and  liable 
to  react  in  the  same  way  again,  even  when  the  external  stimu- 
lus is  not  present.     When  this  inner  neural  activity  takes 
place  again  we  have  the  phenomenon  of  recall.     It  is  reason- 
able  to  suppose   that  a  given  brain  centre  cannot  arouse 
itself  to  activity,  but  that  it  acts  only  when  other  centres, 


242 


PSYCHOLOGY 


given     Centre. 


This  supposition  is  backed  up  by  the  facts  of  mental  re-pres- 
entation. Whenever  a  particular  event,  or  object,  is  re- 
called, observation  will  show  that  we  are  reminded  of  the 
event  or  object  by  some  thought  or  presentation  already  in 
consciousness.  We  recall  past  events  by  means  of  their  asso- 
ciates. Any  thought,  percept,  or  image  already  in  the  mind 
tends  to  arouse  the  experiences  which  have  been  associated 
with  it,  because  our  experiences  are  chained  together  by  asso- 
ciation. Given  any  single  link  in  the  chain,  we  are  able,  in  re- 
productive consciousness,  to  repass  to  the  other  links  by 
virtue  of  these  associative  connections.  What  is  the  real  ex- 
planation of  the  fact  that  we  recall  our  experiences  in  the 
general  order  and  scheme  in  which  they  took  place  ?  Why  is 
it  that  the  thought  of  2  X  4  is  followed  by  the  thought  of  8  ? 
Why  does  the  sight  of  my  friend's  dog  bring  up  the  mental 
image  of  my  friend  himself?  Thgjusual  answer  that  such 
sequences  of  conscious  states  are  determined  by  the  law  of  ag- 
sociatipn,  only  restates,  or  rather  generalizes,  tb^  fyrts  ag  y/p 
know  them.  It  does  not  explain  them.  The  explanation  is 
to  be  found  in  the  nature  of  the  nervous  connection  between 
the  cortical  areas  involved  in  the  original  experiences.  We 
may  suppose  that  if  the  neural  activity  in  a  given  brain  centre 
is  followed  or  accompanied  by  the  stimulation  of  another 
centre,  that  the  pathway  between  the  centres  is  opened  and 
there  is  a  passage  of  nervous  energy  over  this  pathway.  The 
two  centres  are  in  a  condition  of  heightened  neural  activity, 
and  are  discharging  their  energy.  Under  such  conditions  it  is 
reasonable  to  suppose  that  the  energy  of  the  one  passes  to  the 
other,  establishing  a  pathway  between  the  centres.  Then,  ac- 
cording to  the  law  of  neural  habit  (that  nervous  impulses  tend 
to  follow  the  pathways  that  they  have  made  on  former  occa- 
sions), we  are  able  to  get  a  general  idea  of  what  happens  in 
the  brain  when  the  sight  of  my  friend's  dog  is  followed  by 
the  revived  image  of  my  friend  himself. 

In  psychological  terms  we  may  say  that  the  process  of 


/  </  *         9  / 

^T^£-^JA^-f^^-*-\  «.     ^ig^e^fc*^  •*•*!     j«^  "" 

~7~   ~r»  i 

MEMORY  243 

recall  follows  the  law  of  habit — that  in  any  series  of  revived 
experiences  each  is  followed  by  one  of  its  former  associates, 
and  any  part  of  a  system  of  thought  tends  to  reinstate  other 
parts  of  it.  But  since  a  single  mental  experience  may  have 
had  a  number  of  different  associates,  what  determines  which 
one  will  be  recalled?  Evidently,  a  given  mental  state  will 
recall  the  associate  that  is  most  closely  connected  with  it,  or, 
to  return  to  neural  terms,  recall  will  follow  the  most  perme- 
able pathways.  The  permeability  of  neural  pathways,  or 
the  closeness  of  association  between  mental  states,  is  deter- 
mined by  any  one,  or  several,  of  the  following  factors:  (i) 
Recency,  (2)  frequency,  (3)  vividness  of  associated  experi- 
ences, (4)  dominant  system  of  thought  or  the  conscious  con- 
text at  the  time  of  recall,  and  (5)  the  plan  or  purpose  present 
in  the  mind. 

Often  it  is  the  most  recent  associate  which  is  revived.  At 
other  times  it  may  be  the  most  frequent  associate,  and  at 
still  other  times  the  vividness  of  an  associated  experience 
may  win  the  day  for  it.  It  may  happen  that  recency  and 
frequency,  or  recency  and  vividness,  may  work  together  to 
recall  an  experience.  Illustrations  of  these  cases  may  be 
easily  supplied  by  the  student.  Usually  the  reproductive 
tendency  of  our  thoughts  is  determined  by  the  nature  of  con- 
sciousness uppermost  at  the  time — by  the  context.  If  one  is 
reading  or  thinking  about  politics,  the  word  "party"  brings 
up  the  thought  of  Republican  or  Democrat.  On  the  other 
hand,  if  the  topic  of  thought  is  set  upon  one's  social  obliga- 
tions, the  word  "party"  may  bring  up  the  thought  of  the 
dinner-party  that  he  should  give  to  repay  his  social  debts. 
In  reading  or  listening  to  a  lecture  it  is  the  context  that 
determines  which  of  the  many  meanings  of  a  word  is  to  be 
recalled.  Recall  is  also  directed  very  largely  by  the  purpose 
or  plan  which  we  have  in  mind.  We  recall  that  which  serves 
the  end  in  view.  If  our  purpose  is  to  remember  the  names 
of  the  Presidents  of  the  United  States,  Washington  is  followed 
by  Jefferson,  rather  than  by  Mount  Vernon  or  the  Delaware. 


244  PSYCHOLOGY 

It  is  plain  that  the  context  of  thought  and  purpose  usually 
work  together.  In  practical  memory  the  process  of  recall  is 
selective.  If  a  given  mental  state  always  recalled  all  its 
former  associates  impartially,  memory  would  become  a  bur- 
den instead  of  an  aid  in  thinking.  As  a  matter  of  fact,  only 
those  associates  which  are  more  or  less  appropriate  to  the 
present  purpose  of  the  mind  are  recalled.  The  general  direc- 
tion which  recall  takes  is,  therefore,  determined  by  the  topic 
of  thought  which  we  select. 

This  form  of  recall,  which  is  guided  and  controlled  by  a 
definite  purpose,  has  been  called  active  or  voluntary  recall,  to 
distinguish  it  from  the  aimless  reproduction  in  reverie  and 
day-dreaming.  However,  we  cannot  directly  will  to  recall 
a  definite  pastexperience,  so  that  the  term  voluntary  recall 
is  misleading^ The  most  that  we  can  do  is  to  search  in  the 
generaldirection  in  which  we^  think  the  desired-£xj3erience 
lies /and  waitjpr  the  Associative  connections  to  revive  it.  In 
most  cases  recall  takes  place  directly  and  immediately.  The 
particular  appropriate  associative  link  becomes  active  the 
moment  the  attention  is  turned  in  the  desired  direction.  For 
instance,  when  I  wish  to  remember  the  name  of  the  first 
President  of  the  United  States  the  associative  connection  be- 
tween "first  President"  and  "Washington"  is  direct  and 
immediate.  But  in  some  cases  the  so-called  voluntary  or 
active  recall  is  indirect.  Suppose  I  try  to  remember  the 
name  of  the  bookseller  who  sold  me  an  old  copy  of  Shake- 
speare. The  thought  of  this  particular  copy  should  bring 
up  directly  the  name  of  the  bookseller,  but  it  fails  to  do  so. 
I  then  review,  one  after  the  other,  all  the  other  associates, 
the  location  of  his  shop,  his  personal  appearance,  the  other 
books  I  bought  of  him,  but  no  one  of  them  is  successful  in 
reviving  his  name.  I  may  then  try  the  method  of  pronounc- 
ing the  letters  of  the  alphabet,  hoping  that  the  sound  of.  the 
first  letter  of  his  name  will  possess  a  sufficiently  strong  repro- 
ductive tendency  to  awaken  the  name.  This  is  often  suc- 
cessful. Thus,  under  the  guidance  of  purpose  we  give  our 


MEMORY  245 

attention  to  the  circumstances  which  we  feel  are  in  any  way 
connected  with  the  forgotten  name,  and  these  associates  do 
the  work  for  us. 

Sometimes  recall  appears  to  be  spontaneous,  i.  e.,  taking 
place  without  the  aid  of  associative  links.  Ideas  and  images 
pop  into  consciousness  without  any  apparent  connection. 
They  seem  to  rise  up  out  of  the  depths  of  consciousness  by 
virtue  of  their  own  force.  Vivid  or  painful  experiences  will 
for^  days  continually  appear  and  reappear.  Likewise,  a  tune 
will  "run  m  the  head"  for  hours.  In  some  cases  these  ap- 
parently isolated  memory  fragments  have  been  found  to  be 
due  to  subconscious  associations,  or  to  such  delicate_asjocja- 
tive  connections  that  they  escape  ordinary  observation.  It 
is,  of  course,  conceivable  Uiat  for  some  time  after  a  brain 
centre  has  been  stimulated  into  action  the  recency  of  the 
action  leaves  it  very  susceptible  to  the  same  kind  of  activity, 
so  that  it  springs  into  action  again  upon  the  slightest  stimu- 
lus, such  as  changes  in  blood  circulation  and  pressure,  free 
energy  from  other  active  centres,  etc.  In  such  cases  asso- 
ciative links  are  not  necessary  for  revival.  In  the  great  ma- 

j^rvjy   ftf   raspg   of    <cpnnfnnem/<:  rprnl.l^    associative   connections 

tljat  are  hidden  from  observation  are  probably  responsible 
for  the  reyjyal.  However,  some  cases  of  recall  seem  to  de- 
pend upon  the  strength  and  vividness  of  the  original  impres- 
sion, rather  than  upon  associative  connections.  A  great 
misfortune,  or  a  great  joy,  will  recur  again  and  again  in  con- 
sciousness without  any  association  nexus. 

(3)  Recognition.  The  final  stage  of  a  memory  process  is 
recognition.  When  a  past  experience  is  revived  and  the  re- 
vival  is  accompanied  by  the  consciousness  that  it  has  been 
experienced  before,  we  have  memory  in  its  exact  sense.  The 
chief  subjective  mark  of  recognition  is  the  feeling  of  f amil- 
iarity.  Whenever  we  remember  an  event  or  object  there 
comes  with  the  sensory  content  of  the  event  or  object  the 
added  feeling-content  of  familiarity.  The  feeling  of  famil- 
iarity is  a  subjective  sign  of  the  degree  of  certainty  of  recog- 


246 


PSYCHOLOGY 


nition.  If  the  feeling  of  familiarity  is  strong  we  are  certain 
of  the  recognition,  but  if  the  feeling  of  familiarity  is  weak  we 
are  doubtful  about  it.  The  feeling  of  familiarity  is  not,  how- 
ever, absolutely  trustworthy.  It  may  accompany  a  false 
memory  act.  It  often  happens  that  a  witness  gives  in  per- 
fectly good  faith  erroneous  descriptions  of  events  which  have 
in  some  way  acquired  a  feeling  of  familiarity,  which  makes 
the  event  real  for  him.  In  some  cases  the  feeling  of  famil- 
iarity may  be  detached  from  and  aroused  independently  of 
the  event  to  which  it  is  normally  attached.  For  instance,  on 
visiting  a  strange  place  for  the  first  time,  the  feeling  may 
suddenly  come  over  me  that  I  have  been  in  this  place  before 
under  the  same  conditions — have  said  the  same  things  that 
I  am  now  saying,  etc.  This  feeling  is  probably  the  familiarity 
feeling  that  belongs  to  some  former  similar  experience,  which 
just  fails  to  be  recalled  itself.  The  present  situation  brings 
up  the  feeling  of  familiarity  without  the  rest  of  the  original 
experience.  In  other  words,  it  is  a  case  of  incomplete 
memory. 

Recognition  may  be  immediate  or  mediate.  Immediate 
recognition  take  place  without  further  recall.  The  experi- 
ence recalled  is  recognized  on  its  own  account.  On  the  other 
hand,  mediate  recognition  does  not  take  place  until  the  asso- 
ciates of  the  recalled  experience  are  also  recalled  and  made 
to  serve  as  a  guarantee  for  it. 

We  often  confuse  recognition  and  memory  in  our  every- 
day thinking.  For  instance,  on  meeting  a  man  the  second 
time  we  may  remark  that  we  remember  him.  We  cannot,  of 
course,  remember  him  since  he  is  at  the  moment  present  to 
the  senses.  What  we  really  mean  is  that  we  recognize  him. 
Our  recognition  on  this  occasion  accompanies  the  perception 
of  the  man,  not  the  revived  image  of  him.  Such  sensory 
recognition  is  probably  possible  in  a  stage  of  development 
where  memory  is  not  yet  developed.  The  child  may  be  able 

recognize  objects  when  he  sees  them,  long  before  he  is 
)le  to  reproduce  images  of  them  when  absent.  Sensory 


fti 


MEMORY  247 

recognition,  therefore,  appears  before  memory  is  possible. 
Later,  when  images  of  former  sensory  experiences  become 
possible,  recognition  attaches  to  them  in  the  same  manner  as 
it  did  formerly  when  the  actual  sensory  experiences  were 
repeated.  Thus,  sensory  recognition  develops  into  ideational 
recognition. 

The  function  of  recognition  in  sensory  experiences  rests  in_ 
the  identification  of  objects  anc[  FYPpn'pnreg  Tf  1>g  f>vfrprnp1y 
valuable  to  us  as  conscious  beings  that,  after  becoming  ac- 
quainted with  the  characteristics  of  an  object,  we  should  be 
able  to  recognize  that  object  when  it  appears  again.  By 
virtue  of  this  recognition  we  can  then  make  use  of  all  our 
previous  knowledge  about  the  object.  We  knnw  what  to 
expect  of  it.  how  it  will  act,  etc.  We  are,  therefore,  prepared 
to  react  to  it  without  going  through  the  process  of  learning 
its  characteristics  again.  This  we  should  be  obliged  to  do 
if  we  did  not  recognize  it.  Thus,  the  child  profits  by  the  I 
recognition  of  nurse,  bottle,  ball,  etc.,  because,  having  learned/ 
their  characteristics  on  former  occasions,  he  can  by  virtue/ 
of  recognition  react  more  advantageously  to  them.  Sensory 
recognition  (recognition  of  objects)  is  really  a  primitive  form 
of  memory — a  method  of  making  use  of  past  experiences. 
Memory  proper  appears  when  the  reproduced  mental  image 
ol  the  object  is  substituted  for  the  presentation  ofthe  object" 
Jtself. 

When  the  same  object  has  been  presented  many  times, 
recognition  of  it  as  a  single  former  experience  tends  to  drop 
out.  We  become  perfectly  familiar  with  it,  and  adjust  our- 
selves to  it  automatically.  The  identification  of  it  as  a  par- 
ticular former  experience  is  then  unnecessary.  Likewise,  in 
memory,  when  the  image  of  an  object  or  event  has  been 
repeated  many  times,  recognition  becomes  less  and  less  prom- 
inent and  finally  disappears,  leaving  the  feeling  of  familiarity 
as  its  representative.  For  instance,  when  we  first  learned  that 
Washington  was  the  first  President,  or  that  4X4  =  16,  our 
memory  of  these  facts  included  the  identification  of  each  as 


248  PSYCHOLOGY 

a  definite  former  experience,  when  and  where  and  how  we 
learned  it.  The  recognition  of  the  memory  image  was  neces- 
sary at  first  as  a  guarantee  that  it  re-presented  a  real  experi- 
ence. But  later  we  accept  the  mere  revival  of  the  image 
without  identification  or  guarantee  other  than  itself,  except 
the  feeling  of  familiarity  which  survives  from  the  earlier  acts 
of  recognition.  Thus,  much  of  our  past  experience  is  revived 
or  re-presented  without  recognition  or  without  being  remem- 
bered  in  the  strict  sense  of  the  term.  All  that  I  know  and 
can  reproduce  of  history,  arithmetic,  geography,  etc.,  and  my 
ability  to  read  and  write  are  the  results  of  former  experi- 
ences, yet  I  do  not  identify  my  present  reproduced  thoughts 
of  this  knowledge  with  these  former  experiences,  nor  am  I 
aware  of  them  as  past  content  of  my  experience.  I  can  re- 
call my  name,  but  the  chances  are  that  I  do  not  think  of  it 
as  a  former  experience.  It  is  merely  reproduced,  or  re- 
presented, not  explicitly  recognized.  However,  the  practical 
result  is  the  same.  It  is  memory  with  an  element  which  has 
ceased  to  be  useful  dropped  out.  Reproduction  under  such 
conditions  is  really  a  stage  of  re-presentative  mental  life  be- 
yond or  above  memory — a  stage  of  re-presentation  where  recog- 
nition  is  no  longer  necessary.  If  we  were  obliged  to  identify 
by  recognition  all  re-presented  mental  content,  even  after  we 
become  familiar  with  it,  our  thinking  and  acting  would  not 
be  as  expeditious  as  it  is. 

However,  without  recognition  in  the  beginning  re-presen- 
tative consciousness  would  be  of  little  value.  For  it  is  plain 
that,  unless  an  image  has  been  at  some  time  certified  to  as 
based  upon  real  experience,  it  can  function  only  as  mere 
fancy.  Recognition,  then,  is  an  important  and  necessary 
phase  of  memory. 

Organic  Memory. — We  often  say  that  we  remember  how 
to  swim,  how  to  skate,  how  to  play  tennis,  etc.  It  is  evident 
that  the  modifications  left  behind  by  former  practice  and 
training  have  been  retained  by  the  organism.  We  can  hardly 
say,  however,  that  such  cases  involve  conscipusrecall.  Where 


MEMORY  249 

these  habits  of  skill  are  perfected  the  organism  reacts  in  the 
same  way  in  the  same  situation,  without  the  aid  of  the  con- 
scious recall  of  former  experiences.  This  form  of  organic 
retention  has  been  termed  organic  memory  by  certain  authori- 
ties. It  is  mentioned  here  in  order  to  differentiate  it  from 
memory  proper. 

Individual  Differences  in  Memory. — There  is  great  vari-v 
ation  in  the  character  of  memory  among  different  indi- 
viduals. Some  have  very  poor  memories,  being  unable  to 
retain  and  recall  only  a  small  part  of  what  they  experience. 
Others  have  prodigious  memories,  retaining  practically  every- 
thing they  see  and  hear.  Most  of  us,  however,  possess  memo- 
ries which  lie  between  the  two  extremes.  It  does  not  follow 
that  unusual  ability  of  memory  gives  great  mental  power,  or 
is  a  sign  of  great  intelligence.  Some  wonderful  memories 
have  been  found  in  idiots. 

Our  memories  are  not  equally  good  for  all  kinds  of  mate- 
rial. Some  have  an  excellent  memory  for  some  things,  and  a 
very  poor  memory  for  other  things.  "Many  a  woman  of 
generally  feeble  memory  can  remember  every  dress  she  has 
owned  since  she  was  ten  years  old,"  says  Thorndike.  The 
story  is  told  of  a  certain  chief  of  criminal  records  in  a  large 
city  who  knew  the  histories  of  the  25,000  criminals  (contained 
on  identification  cards  in  the  bureau),  but  who  on  one  occa- 
sion could  not  remember  his  home  telephone  number.  In 
many  cases  memory  follows  the  types  of  imagination,  i.  e., 
some  remember  best  what  they  see  (visual  type),  others 
remember  best  what  they  hear  (auditory  type).  Pillsbury, 
the  American  chess-player,  possessed  a  wonderful  visual 
imagination  and  memory.  Blind  Tom,  the  blind  musician, 
who  could  remember  and  reproduce  long  musical  selections 
after  hearing  them  once,  had  a  very  poor  memory  for  other 
material.  Such  cases  illustrate  the  fact  that  we  possess  not 
a  memory,  but  rather,  many  memories.  One  of  the  most 
marked  differences  in  the  character  of  memory  is  furnished 
by  the  nature  of  recall.  Some  persons  have  what  James  calls 


/$T 


250  PSYCHOLOGY 

desultory  memory — a  memory  with  a  marked  tendency  to  recall 
past  experiences  only  in  the  order  of  their  original  occurrence. 
Such  memories  grind  out  their  grists  just  as  they  were  put 
into  the  mill,  or,  to  use  another  figure,  they  are  like  phono- 
graphs, reproducing  impressions  in  the  same  manner  that 
they  were  received.  An  excellent  illustration  of  this  form  of 
recall  is  found  in  Jane  Austen's  "Emma,"  quoted  by  James:1 

"But  where  could  you  hear  it?"  cried  Miss  Bates.  "Where  could 
you  possibly  hear  it,  Mr.  Knightley  ?  For  it  is  not  five  minutes  since 
I  received  Mrs.  Cole's  note — no,  it  cannot  be  more  than  five  or,  at 
least,  ten — for  I  had  got  my  bonnet  and  spencer  on,  just  ready  to 
come  out — I  was  only  gone  down  to  speak  to  Patty  again  about  the 
pork — Jane  was  standing  in  the  passage — were  you  not,  Jane?  For 
my  mother  was  so  afraid  that  we  had  not  any  salting-pan  large  enough. 
So  I  said  I  would  see,  and  Jane  said,  'Shall  I  go  down  instead? — for 
I  think  you  have  a  little  cold  and  Patty  has  been  washing  the  kitchen.' 
'Oh,  my  dear,'  said  I — well,  and  just  then  came  the  note.  A  Miss 
Hawkins — that's  all  I  know — a  Miss  Hawkins,  of  Bath.  But,  Mr. 
Knightley,  how  could  you  possibly  have  heard  it?  For  the  very 
moment  Mr.  Cole  told  Mrs.  Cole  of  it,  she  sat  down  and  wrote  to  me. 
Ay.  Miss  Hawkins " 


?he  nature  of  the  recall  in  such  a  sequence  of  reproduced 
\jf  experiences  is  known  as  " '  total^recMJ^  i.  e.,  every  idea  acts 
^*     as  a  whole  in  calling  up  the  next  idea.     The  present  mental 
content  is  not  broken  up  or  analyzed.     There  is,  therefore, 
no  selection  of,  or  emphasis  placed  upon  any  one  part  of  it. 
As  a  result,  only  those  experiences  which  have  been  associated 
with  it  as  a  whole  are  recalled — a  superficial  way  of  thinking. 
On  the  other  hand,  some  persons  have  ' '  logical -fliemaries ' ' 
—memories  in  which  recall  follows  the  logical  connection  of 
thoughts  or  experiences.     Two  things  which  happen  together 
may  not  have  any  vital  relationship  whatever.     Therefore,  in 
the  logical  mind,  they  are  not  put  together,  and  so  are  not 
revived  together  in  reproduction.     The  lojriail_memory  is 
highly  selective.     It  breaks  up  the  present  presented  situa- 
tl5n  or  thought  into  its  more  elemental  parts,  one  of  which 

1  "Principles  of  Psychology,"  vol.  I,  p.  571. 


MEMORY  251 

acts  as  a  connecting-link  in  recall.     This  is  known  asJi^artial  .. 
recqU^i.  e.,  ajmrt  of  a  thought  or^situatiqn  ^alls  up  the_next  • 
thougKt  inTany  jeque^ce'ofinental  images.     Persons  who  re-  * 
call  in  this  way  possessthe~ar3ility~to^see~the  subtle  and  logical 
connections  which  exist  between  things.     They  attend  to  the 
relationships  of  similarity  ajid  identity,  and  not  merely  to  the 
superficial  fact  that  T;wo  events  take  place  at  the  same  time 
or  successively.     To  illustrate  the  difference  between  total 
and  partial  recall:  Suppose  the  sight  of  the  lamp  on  my  desk 
recalls  the  shop  where  I  bought  it.     Here  the  perception  of 
the  lamp  as  a  whole  connects  with  a  past  associate  (total  re-  %> 
call).     But,  suppose  the  sight  of  the  lamp  makes  me  think  of  "  v 
the  sun.     In  this  case  the  connecting-link  is  not  the  lamp  as 
a  whole  but  a  part  of  it — its  luminosity  (partial  recall) . 

We  often  speak  of  the  memory  in  which  recall  takes  place 
without  logical  connections  as  rote  memory^  In  this  case  there 
are  no  inner  relationships  between  the  things  recalled.  The 
only  connection  rests  in  the  fact  that  they  have  been  experi- 
enced together  (association  by  mere  contiguity).  Notice  the 
difference  in  the  mental  connections  of  the  terms  of  the  list 
of  nonsense-syllables:  seg-bom-wek-caf-lon-dut-rin-foh-gal-gif, 
and  those  in  the  list  of  sense- words:  teacher-school-pupil-spell- 
write-read-book-pencil-paper.  When  trying  to  remember 
them  the  nonsense-syllables  are  recalled  by  rote  memory,  while 
memory  of  the  sense-words  makes  use  of  the  logical  connec- 
tions. 

In  some  cases  we  find  very  extensive  memory  of  the  desul- 
tory type.  Great  masses  of  material  are  retained,  but  the 
facts  may  not  be  properly  organized.  The  result  is  that,  as 
was  the  case  of  Dominie  Sampson,  "its  owner  can  never  lay 
his  hands  on  any  one  article  at  the  moment  he  has  occasion 
for  it."1  The  readiness  with  which  a  memory  recalls  what  is 
relevant  to  a  given  situation  is  called  its  "serviceableness"  by 
Stout. 

'Quoted  from  "Guy  Mannerin^"  (in  Stout's  "Manual  of  Psychology,"  p. 
437-) 


PSYCHOLOGY 

The  Training  of  the  Memory. — Retention  depends  upon 
the  character  of  the  brain  tissue — it  native  tenacity.  "This 
is  a  physiological  quality,  given  once  for  all  with  an  individ- 
ual's organization,  and  which  he  can  never  hope  to  change."1 
According  to  James,  this  native  retentiveness  cannot  be  im- 
proved by  training.  While  we  may  grant  the  truth  of  this 
statement,  we  must  not  forget  that  there  is  another  impor- 
tant condition  of  memory,  also  mentioned  by  James,  viz.,  the 
number  and  character  of  brain  paths  connecting  any  centre 
with  other  centres.  In  psychological  terms,  the  greater  num- 
ber of  appropriate  associates  a  fact  has,  the  oftener  it  is 
thought  in  these  connections,  and  the  more  vivid  the  atten- 
tion given  to  it,  the  more  easily  it  will  be  recalled.  This 
means  that,  by  properly  organizing  and  classifying  the  ma- 
terial of  memory,  by  repeating  it  a  sufficient  number  of  times, 
and  by  carefully  attending  to  the  things  we  wish  to  retain, 
the  memory  for  any  particular  fact  or  group  of  facts  may  be 
improved. 

There  is  an  erroneous  popular  conception  that  the  memory 
is  something  that  may  be  taken  out  and  exercised,  as  a  trainer 
exercises  his  horse,  and  that  the  exercise  of  memory  in  any 
kind  of  subject-matter  improves  it  for  all  kinds.  We  have 
touched  upon  this  point  before,  when  we  called  attention  to 
the  fact  that  we  do  not  have  a  memory,  but  memories.  Im- 
provement of  the  memory  for  language  does  not  improve  the 
memory  for  mathematics,  except  in  so  far  as  we  learn  meth- 
ods of  study  and  logical  organization  in  the  study  of  the 
one  which  can  be  applied  to  the  study  of  the  other.  Im- 
provement in  the  memory  of  one  kind  of  material  aids  in 
the  memory  of  another  kind  only  in  so  far  as  the  meth- 
ods of  organizing  and  learning  the  different  materials  over- 
lap. 

We  may  say,  then,  that  mere  retentiveness  of  im- 
pressions depends  upon  the  kind  of  brain  tissue  one  has,  but 
that  the  power  of  fixing  and  recalling  any  particular  impres- 
1  James's  "Principles  of  Psychology,"  vol.  I,  p.  664. 


MEMORY  253 

sion  depends  upon  the  number  of  associates  which  we  form 
with  it,  the  frequency  with  which  we  review  its  connection 
and  the  degree  of  attention  given  to  it.  Further,  all  these 
factors  except  the  native  character  of  the  brain  are  under  the 
control  of  the  individual  and,  therefore,  one  may  improve 
the  memory  for  any  kind  of  material  by  practice.  In  fact  we 
may  say,  in  general,  that  any  training  which  causes  us  to 
consider  facts  fully  and  thoroughly,  to  associate  them  logi- 
cally, to  review  them  from  time  to  time  from  different  points 
of  view,  and  to  connect  them  with  our  interests,  will  improve 
the  memory  for  such  facts. 

Methods  of  Memorizing. — The  most  prominent  methods 
of  memorizing  are:  (i)  Repetition,  (2)  Concentration,  (3)  Re- 
call, (4)  Sectional,  (5)  Entire.  By  going  over  and  over  again 
the  same  material  it  will  with  a  sufficient  number  of  repetitions 
become  fixed  in  memory,  but  experiments  have  proven  this 
method  to  be  wasteful  of  time.  Prolonged  and  intense  con-, 
centration  of  the  attention  is  much  more  efficacious  than  a 
mere  mechanical  repetition.  Cafefurexperiments  have  estab- 
lished the  fact  that  the  method  of  recall  is  the  best.  This 
method  is  more  in  accord  with  the  actual  conditions  under 
which  practical  memory  works.  It  requires  the  arousal  of 
the  memory  material  from  within  just  as  we  recall  it  in  actual 
memory.  This  method  requires  that  after  one  or  two  im- 
pressions from  without,  the  subject  then  tries  to  recall  the  ma- 
terial. If  not  successful,  it  is  gone  over  once  more,  and  again 
attempts  are  made  to  recall  it.  This  process  is  kept  up  until 
the  material  is  learned.  In  this  way  the  most  active  partici- 
pation of  the  learner  is  called  forth.  In  memorizing  a  poem, 
paragraph  of  prose,  or  other  material,  it  is  a  very  common 
practice  to  use  the  sectional  method.  The  material  is  divided 
into  small  sections  and  each  section  learned  separately.  This, 
again,  has  been  found  wasteful.  No  division  should  be  made 
in  learning  that  is  not  required  at  the  time  of  reproduction. 
The  entire  method1  is  more  economical  and  trustworthy.  Each 

1  Sometimes  called  the  "global  method." 


PSYCHOLOGY 

unit  of  whatever  material  is  to  be  learned  should  be 

I       gone  over  from  beginning  to  end  to  get  the  best  results. 
JN        With  regard  to  the  distribution  of  time  devoted  to  mem- 

*  orizing  any  given  subject-matter,  it  has  been  found  uneco- 
.  J>|nomical  to  force  the  learning  process  by  continuous  repetitions 

\  without  pause.     It  is  better  to  give  a  few  minutes  each  day 
'  if  or  a  number  of  days  than  to  concentrate  the  same  time  of 

-  leffort  into  one  day.     The  total  time  required  is  less  and  the 
impressions  are  more  firmly  fixed  when  the  time  for  learning 
is  thus  distributed  than  when  it  is  all  given  at  a  single  sitting 
without  intermission.     Fifteen  minutes  a  day  for  twenty  days 

f  brings  about  better  results  than  sixty  minutes  a  day  for  five 
Y  days. 

.  i  The  greater  the  number  of  appropriate  logical  connections 
1 1  that  are  attended  to  and  emphasized  in  memorizing,  the 
1 1  shorter  the  time  of  learning  and  the  more  permanent  the 
acquisition.  Thus,  with  one  subject  it  required  fifty-nine 
repetitions  to  learn  a  series  of  thirty-six  nonsense-words,  while 
a  verse  of  poetry  containing  thirty-six  words  required  only 
ten  repetitions.  Twenty-four  hours  later  he  had  forgotten 
65  per  cent  of  the  nonsense-words  as  against  45  per  cent  of 
the  poetry.  Rational  associations  were,  therefore,  much  more 
effective  than  the  mechanical  connections  of  rote  memory, 
both  in  the  acquisition  and  retention  of  material. 

Forgetting. — We  have  already  seen  that  those  things  to 
which  we  give  our  attention  make  the  deepest  and  most  last- 
ing impressions.  Attention  is  never  evenly  divided  over  the 
field  of  our  experience.  It  is  concerned  with  certain  portions, 
while  it  neglects  or  slights  others.  The_4iijrtions__which-lie 
outside  the  focus  of  attention  impj^sjjas_less_deepjy_j_and  are 
therefore  more  easily  lost.  Consequently,  forgetting  is  as 
normal  a  function  of  consciousness  as  remembering.  If  we 
ir  V*  i  were  obliged  to  carry  in  memory  all  the  events  of  our  experi- 
yjr  /"  ence  we  should  find  ourselves  swamped  by  a  great  mass  of 
irrelevant  and  insignificant  details. 

But,   forgetfulness  normally  extends  to  the  experiences 


MEMORY  255 

which  have  enjoyed  the  fulness  of  attention.  Although  it 
may  cause  us  great  inconvenience  at  times,  there  are  certain 
advantages  in  being  freed  from  the  burden  of  the  past.  The 
factors  which  lead  to  such  lapses  of  memory  are  very  numer- 
ous and  refuse  to  be  placed  under  any  one  principle.  1^  ijs 
generally  and  popnforly  believed  that  disagreeable  and  painful  < 
experiences  are  not  forgotten.  This.  TTowever,  is  not  true. 
There  is  a  marked  tendency  to  forget  the  disagreeable.  The 
things  that  we  do  not  like  —  our  past  pains  and  unpleasant 
experiences  —  drop  into  the  background  of  consciousness 
sooner  than  the  agreeable  experiences.  Usually  we  forget  -^u 
quickly  that  which  we  learn  quickly,  for  the  reason  that  in 
the  rapidity  of  acquisition  few  associative  connections  are 
formed.  Examples  of  this  are  foxind  in  cramming,  where 
practically  everything  is  forgotten  after  examinations,  or,  in 
the  case  of  the  lawyer  who  quickly  learns  all  the  facts  bear- 
ing on  a  particular  case  but  promptly  forgets  them  after  the  -jr 
trial.  Things  in  which  wft  lose  intpjyst  are  quickly  forgotten,  u 
for  the  reason  that  we  do  not  think  of  them  and  revive  them. 
Likewise,  acquisitions  of  mer^oyy  wKirh  ^e  not  used  and 
kep_t_fresh  gradually  fade  out  qf_conscipusiie5s.  Failure  to 
use  a  foreign  language  results  finally  in  its  loss.  However,  a 
very  instructive  fact  comes  to  light  in  such  cases.  It  has 
been  found  that  the  time  taken  to  relearn  forgotten  material 
is  much  less  than  that  originally  required,  showing  that  the 
material  was  not  entirely  lost  —  that  the  effects  of  the  former 
experience  were  really  retained.  This  has  led  some  authori- 
ties to  declare  thaJL_nothmg  is  ever  comrjletejy  lost  —  that 
whatever  we  learn  persists,  and  is  a  factor  in  determining 
our  conscious  states  even  though  it  may  not  be  recalled. 
There  is  much  truth  in  this  view,  although  it  is  difficult  to 
determine  exactly  how  much  the  residue  of  our  past  experi- 
uences  th£jcfiara£teT2!or~c^risciousness.  In  some 
cases  we  know  thatthe  influenceis  considerable.  It  is  safe 
to  say  that  even  though  the  form  of  our  impressions  is  for- 
gotten their  essential  substance  remains  beneath  the  surface 


\j^ 


256  PSYCHOLOGY" 

of  memory.  Every  experience  plays  its  part  in  the  fashioning 
of  our  mental  characteristics  and  leaves  its  mark,  although 
its  outline  may  be  effaced  by  the  lapse  of  time.  We  often 
hear  persons  of  intelligence  express  the  opinion  that  they 
have  wasted  their  time  absolutely  on  this  or  that  study  in 
college  because  they  have  forgotten  it.  The  more  we  exam- 
ine the  nature  of  mental  life  the  more  we  are  convinced  of  the 
error  of  such  a  view. 

Such  are  some  of  the  conditions  of  normal  forgetfulness. 
Special  cases  of  forgetting,  sometimes  amounting  to  complete 
loss  of  memory,  accompany  certain  changes  and  abnormal 
conditions  of  the  organism.  Old  age,  fatigue,  bodily  disease, 
accidents,  exhibit  peculiar  forms  of  forgetting.  With  the  ad- 
vancing general  dissolution  of  the  nervous  material  in  old 
age,  experiences  fail  more  and  more  to  be  retained.  This  ac- 
counts for  the  fact  that  old  people  easily  forget  recent  experi- 
ences, and  live  more  and  more  in  the  memories  of  their  youth. 
They  lose  their  memories  in  the  reverse  order  of  acquisition.. 
Their  first  experiences  are  the  last  to  be  forgotten.  This  is 
in  accordance  with  the  law  of  regression:  The  dissolution  of 
the  nervous  system  takes  place  in  the  reverse  order  of  its  develop- 
mcnt.  The  earliest  functions  are  the  most  stable  and  the  last 
to  be  affected.  On  the  other  hand,  the  latest  functions  are 
less  stable  and  the  first  to  be  affected  in  general  decay.  The 
loss  of  memory  as  one  gets  older  differs  for  different  kinds  of 
materials.  The  words  for  concrete  ideas  are  more  easily  for- 
gotten than  those  for  abstract  ideas.  Thus,  proper  nouns 
are  forgotten  before  adjectives  and  verbs.  The  reason  for 
this  lies  in  the  fact  that  the  connections  between  the  name  of 
a  particular  object  and  the  object  itself  are  less  frequently 
made  than  in  the  case  of  abstract  ideas.  The  particular  ob- 
/  ject  may  be  thought  of  or  imaged  without  the  word,  while 
the  thought  of  an  abstract  idea  involves  the  image  of  the 
word  in  nearly  every  instance.  Therefore,  it  is  more  firmly 
fixed  and  has  more  associative  connections  for  memory  to 
work  upon.  Consequently,  the  weakening  of  associative  con- 


MEMORY  257 

nections  in  old  age  affects  the  names  for  particular  things  be- 
fore it  does  those  for  general  ideas. 

In  extreme  fatigue  there  is  a  marked  falling  off  in  ability 
to  recall,  especially  the  ability  to  recall  language  symbols. 
When  fatigued,  words  come  to  us  hesitatingly,  and  at  times 
the  right  word  cannot  be  revived  at  all.  In  cases  of  severe 
illness  accompanied  by  high  fever  there  is  often  a  complete 
lapse  of  memory.  A  similar  loss  of  memory  may  be  noted 
during  periods  of  extreme  excitement  or  emotional  distur- 
bance. An  interesting  lapse  of  memory  takes  place  after  an 
accident  in  which  we  lose  consciousness.  On  recovery  we 
find  that  we  are  unable  to  recall  the  events  which  led  up  to 
the  accident.  We  may  forget  the  events  of  minutes,  hours, 
or  even  days  preceding  the  accident.  A  blow  upon  the  head 
may  in  extreme  cases  cause  us  to  forget  all  our  past  experi- 
ences. Sometimes  it  may  cause  a  partial  loss  of  memory 
only — memory  for  a  certain  class  of  facts,  a  foreign  language 
which  we  have  acquired,  or  specific  forms  of  sensory  content 
— visual  or  auditory  images  of  certain  kinds. 

Defects  of  Memory. — Defects  of  memory  have  been  classi- 
fied into  three  groups:  (i)  Amnesia,  or  loss  of  memory,  (2) 
Hypermnesia,  or  exaltation  of  memory,  and  (3)  Paramnesia, 
or  falsification  of  memory.1 

Amnesia  is  the  inability  to  form  or  retain  mental  impres- 
sions. General  amnesia  is  best  represented  in  idiots,  in  cases 
of  dementia,  or  extreme  old  age,  when  a  weakened  mentality 
makes  the  acquisition  and  retention  of  any  form  of  memory 
material  impossible.  Partial  amnesia  is  the  inability  to 
recall  certain  groups  of  experiences,  as,  for  instance,  when 
the  patient  cannot  remember  letters,  the  names  of  his  friends, 
or  the  knowledge  of  Latin,  or  other  languages,  while  memory 
for  other  things  is  normal.  Such  loss  of  memory  may  follow 
illness  or  injury  to  the  brain. 

'For  a  more  extended  classification,  see  article,  "Memory  (Defects  of)," 
by  Professor  T.  Jastrow,  in  Baldwin's  "Dictionary  of  Philosophy  and  Psychol- 

ogy." 


258  PSYCHOLOGY 

Hypermnesia  is  an  exalted  power  of  memory.  It  usually 
exhibits  itself  as  an  unusual  ability  to  remember  certain 
groups  of  facts  or  impressions.  This  abnormality  of  memory 
is  the  basis  of  the  marvellous  feats  of  mental  reproduction 
that  are  sometimes  reported.  Blind  Tom,  who  could  remem- 
ber a  long  selection  of  difficult  music  after  hearing  it  once, 
and  Seneca,  who  claims  that  he  was  able  to  repeat  two  thou- 
sand names  in  the  order  that  they  were  read  to  him,  illustrate 
this  exalted  form  of  memory. 

Paramnesia  is  a  defect  of  recognition,  so^^times  called 
illusions  of  memory.  In  some  cases  a  purely  imaginative 
scene  or  event  may  be  accompanied  by  a  false  recognition, 
making  it  appear  to  the  subject  as  a  real  occurrence.  Many 
of  the  delusions  of  insanity  are  of  this  nature.  In  more  nor- 
mal  individuals  a  pure  fabrication  may,  after  being  repeated 
many  times,  acquire  a  false  recognition,  so  that  such  indi- 
viduals come  in  time  to  believe  their  own  stories.  It  may 
also  cause  that  strange  "feeling  that  all  this  has  happened 
before"  which  every  one  has  at  times  experienced.  In  such 
cases  the  recognition  of  some  similar  former  experience  mo- 
mentarily but  falsely  attaches  itself  to  the  present  event. 
The  opposite  process  may  sometimes  take  place,  when  a 
familiar  scene  may  temporarily  appear  to  us  as  new  and 
strange.  Here  the  associative  connections  are  severed  for 
the  time,  and  the  feeling  of  familiarity  drops  away  and  is 
replaced  by  the  feeling  of  strangeness  or  unfarniliarity.  This 
may  be  produced  experimentally:  Pick  out  a  familiar  word 
like  "and"  on  a  page  of  print.  Stare  at  it  for  several  min- 
utes, and  presently  it  will  appear  as  a  foreign  and  unfamiliar 
thing.  The  explanation  lies  in  the  fact  that  the  meaning  of 
the  word,  its  associative  connections,  drops  away  from  the 
perception,  taking  with  it  the  feeling  of  familiarity.  Illusions 
of  memory  may  also  be  brought  about  by  suggestions.  In 
the  process  of  "sweating"  a  witness  by  detectives  and  police 
officers  the  normal  associative  connections  are  weakened  by 
the  extreme  mental  fatigue  and  excitement;  caused  by  the 


MEMORY  259 

inquisition.  Under  such  conditions  a  highly  nervous  or  men- 
tally  unstable  witness  becomes  a  prey  to  suggestion,  and  may 
be  made  really  to  feel  that  he  saw  or  took  part  in  events 
entirely  foreign  to  him.  He  may  in  this  way  be  induced  to 
give  false  testimony.  Children  are  especially  subject  to  falsi- 
fication of  memory  by  suggestion.  It  is,  therefore,  extremely 
unsafe  to  depend  upon  the  testimony  of  children,  elicited  by 
questions  containing  even  the  slightest  suggestions  in  them. 
Function  of  Memory. — In  our  study  of  memory  we  should 
not  lose  sight  of  the  fact  that  its  real  function  is  not  the  mere 
impartial  reproduction  of  the  past,  but  the  revival  and  iden- 
tmcatipn  of  only  thosepastexrjeriences  whichare  appropjriate 
to  the  needs  of  the  present  "situation— ^5ie  seTe^ionofjLhose 
pertinent  parts  of  the  past  which  can  be  incorporateoTinto 
our  present  thinking  and  acting.  While  this  selection  is 
largely  controlled  by  the  nature  of  past  associations,  the 
revival  of  these  associations  in  all  cases,  save  probably  in 
mere  fancy  or  day-dreaming,  takes  place  within  larger  move- 
ments of  consciousness  dominated  by  purposes,  plans,  desires, 
feeling,  and  volitional  impulses.  The  memory  process,  then, 
does  not  stand  by  itself,  but  is  involved  in  larger  complexes 
of  consciousness  in  whose  interests  it  functions.  It,  however, 
plays  no  insignificant  part  in  our  larger  conscious  life.  It 
frees  us  from  the  narrow  limits  of  the  present  moment,  and 
enlarges  the  mental  horizon  by  re-presenting  conscious  experi- 
ences of  the  past  to  which  it  gives  the  stamp  of  reality  and 
genuineness. 

^     QJ^J^^O^^^-  o^^^^^ 
V' 


?^3*         »*• 


CHAPTER  XI 
IMAGINATION 

Memory  and  Imagination. — We  have  seen  that  the  ability 
to  form  mental  images  of  past  impressions  is  the  basis  of 
memory.  Since  imagination  in  its  larger  sense  means  the 
process  of  forming  reproductive  as  well  as  productive  images, 
it  follows  that  memory  and  imagination  overlap. 


tiye  imagination  is  realty  a  part  of  memory.  Memory  in  its  \1 
exact  sense  is  the  definite  recognition  and  identification  of  ** 
these  reproductive  images.  But  in  many  cases  the  purpose 
of  thinking  does  not  require  that  reproductive  consciousness 
should  advance  to  the  stage  of  recognition.  In  such  cases 
the  sensory  contents  of  former  experiences  are  merely  revived 
but  not  recognized.  The  reproduction  of  a  past  experience 
does  not  always  involve  the  recognition_of  it.  For  example, 
m  contemplating  my  summer  outing,  fleeting  images  of  places 
and  routes  of  travel  may  arise  in  my  mind  without  any  con- 
sciousness of  the  fact  that  I  have  experienced  them  before. 
In  geometry  I  may  image  a  right-angled  triangle  without 
recognizing  it  as  any  definite  former  experience.  In  percep- 
tion, I  am  constantly  supplementing  actual  sensations  given 
by  the  stimulus  by  images  based  upon  past  experiences,  but 
I  do  not  recognize  or  identify  them  as  such,  and  so  I  cannot 
be  said  to  remember  them. 

The  amount  or  degree  of  recognition  accompanying  repro- 
ductive images  may  vary  from  clear  and  vivid  to  vague  and 
hazy  recognition.  Reproductive  imagination  and  memory, 
therefore,  shade  off  gradually  into  each  other,  so  that  it  is 
sometimes  difficult  to  say  whether  a  given  image  is  a  memory 
image  or  an  image  of  reproductive  imagination.  As  we  have 
already  said,  for  the  popular  mind  reproductive  imagination 

260 


IMAGINATION  261 

passes  for  memory.     This  finds  a  partial  justification  in  the 
overlapping  of  memory  and  reproductive  imagination,  and  in 
the  gradual  shading  of  the  one  into  the  other.     But  in  the 
more  critical  analysis  of  psychology  we  are  forced  to  make  a' 
distinction  between  them. 

Kinds  of  Imagination. — The  most  striking  thing  about 
imagination  is  the  formation  of  images  of  things  which  have 
never  been  given  in  actual  experience — "  creations  of  the 
imagination,"  as  the  popular  phrase  goes.  Our  power  to 
think  events  that  never  happened  to  us,  to  mentally  picture 
things  that  we  never  saw,  or  even  to  image  things  that  never 
existed  is  what  is  commonly  meant  by  imagination. 

There  are,  then,  two  kinds  of  imagination:  (i)  Reproductive 
imagination — the  imagination  which  reproduces  former  ex- 
periences, and  (2)  productive  imagination,  which  constructs 
mentally  things  which  we  have  never  experienced  before. 
Productive  imagination  may  function  in  the  interest  of  some 
plan  or  purpose,  or  it  may  act  spontaneously,  i.  e.,  unre- 
strained by  any  purpose  or  voluntary  effort  on  our  part.  The 
former  we  shall  call  constructive  imagination,  and  the  latter 
fancy.  Constructive  imagination  may  be  further  divided  ac- 
cording to  the  general  field  in  which  it  operates.  The  follow- 
ing is  an  outline  of  the  different  kinds  of  imagination  so  far 
mentioned. 

.  I.    Reproductive  Imagination. 
II.    Productive  Imagination. 

1.  Constructive. 

(a)  Scientific, 
(ft)  Mathematical, 
i  (c)  Literary. 
(d)  Artistic. 

2.  Fancy. 

I.  Reproductive  Imagination. — Hobbes  called  attention  to 
two  kinds  of  imagination,  the  one,  "as  when  one  imagineth  a 
man  or  horse  which  he  hath  seen  before"  and  the  other  "as 


262  PSYCHOLOGY 

when  from  the  sight  of  a  man  at  one  time  and  a  horse  at 
another,  we  conceive  in  our  mind  a  centaur."  Such  is  the 
difference  between  reproductive  and  productive  imagination. 
The  former  merely  reproduces  our  past  sensations  and  per- 
ceptions. Images  are,  however,  never  exact  duplicates  of 
former  experiences,  for  otherwise  we  should  confuse  them. 
We  always  know  the  difference  between  the  image  and  the 
actual  sensory  experience,  except  in  the  case  of  hallucinations. 
The  psychological  differences  between  the  image  and  the  per- 
ception we  have  already  pointed  out  in  the  first  section  of 
/the  chapter  on  memory.  In  some  abnormal  conditions,  these 
differences  become  obliterated,  and  the  image  may  then  take 
°n  the  reality  of  perception.  It  is  reported  of  an  English 
portrait-painter  that  his  reproductive  visual  images  were  so 
vivid  that  he  required  only  one  sitting  of  his  subject.  After 
that  he  was  able  to  image  the  position,  features,  clothes,  etc., 
of  the  subject  so  clearly  that  he  could  finish  the  portrait 
without  the  presence  of  the  subject. 

n.  Productive  Imagination.  —  Reproductive  imagination 
is  limited  in  its  range  and  variety  by  the  range  and  va- 
riety of  perceptual  experiences.  On  the  other  hand,  produc- 
tive imagination  is  free.  This  last  statement  needs  modi- 
fication. For  even  productive  imagination  depends  upon 
past  experiences.  Imagination  cannot  create  a  new  world. 
We  cannot  imagine  things  entirely  new,  for  the  material  of 
imagination  must  come  from  the  past.  The  most  fantastic 
creature  of  the  imagination  is  formed  out  of  the  sensory  ele- 
ments of  our  actual  perceptions.  Try  as  hard  as  we  may, 
our  wildest  fancies  cannot  transcend  the  elementary  forms  of 
real  experiences.  Sensation  is  therefore  the  basis  of  all  forms 
of  imagination.  A  highly  productive  imagination  calls  for  a 
broad  basis  of  perception  to  draw  upon.  The  productivity  of 
imagination  consists,  therefore,  in  recombining  the  elements 
of  old  and  familiar  experiences  into  new  forms. 

Reproductive  images  may  be  incorporated  into  productive 
imagination,  as,  for  example,  when  we  combine  the  head  of 


IMAGINATION  263 

a  man  and  the  body  of  a  horse  to  form  a  centaur.    Further, 
an  image  of  productive  imagination  may  vary  only  slightly 
from  some  former  experience,  or  it  may  differ  in  a  marked 
degree  from  it.    There  is  no  absolute  distinction  between  ^ 
reproductive  and  productive  imagination.    The  difference  is  a* 
relative  one,  resting  in  the  degree  to  which  any  given  image < 
corresponds  to  original  experiences. 

The  products  of  productive  imagination  may  vary  from 
the  most  fantastic  dream  to  the  great  creations  of  art,  litera- 
ture, science,  invention,  etc.  And  here  we  make  a  distinction 
between  the  imagination  that  works  according  to  some  plan 
or  purpose  and  is  controlled  and  guided  by  voluntary  effort, 
and  the  imagination  that  is  uncontrolled — without  purpose 
or  plan,  capricious,  and  eccentric.  There  is  a  difference  be- 
tween the  imagination  that  produces  a  poem  or  drama,  a 
painting  or  symphony,  and  the  imagination  that  builds  air- 
castles.  The  first  we  call  (i)  constructive  imagination;  the 
second  is  mere  (2)  fancy.  These  two  kinds  of  imagination 
are  sometimes  called  active  and  passive  imagination.  Con- 
structive imagination  is  active  in  the  sense  that  voluntary  con- 
trol is  present,  holding  the  mental  construction  to  a  definite 
plan.  Fancy  is  passive  in  the  sense  that  images  arise  sponta- 
neously— without  any  apparent  active  control  from  within. 
In  this  case,  whatever  happens  to  arise  in  consciousness  is 
passively  received  without  effort  on  our  part  to  restrict  or 
restrain  it. 

Constructive,  or  active  imagination  manifests  itself  in  (a) 
scientific  and  (b)  mathematical  theories,  and  in  (c)  literary  and 
(d)  artistic  productions,  and  in  other  ways.  The  builder,  the 
inventor,  the  author,  and  the  artist,  as  well  as  the  man  of 
science,  all  rely  upon  constructive  imagination.  Although  it 
is  commonly  said  that  the  artist,  the  builder,  the  author, 
etc.,  are  free  from  all  objective  control — are  free  to  create 
subjectively  their  worlds  of  ideal  existences — this  freedom  is 
only  relative.  No  creation  of  art  can  wholly  disregard  the 
world  as  it  really  is.  The  true  artist  must  constantly  keep 


264  PSYCHOLOGY 

the  laws  of  nature  in  mind.  Likewise,  while  the  author  may 
invent  new  scenes  and  create  ideal  men  and  women  to  enact 
them,  nevertheless  he  is  controlled  in  the  formation  of  his 
imaginary  world  by  the  laws  of  human  nature.  He  incorpo- 
rates the  real  characteristics  of  actual  scenes  and  real  people 
in  his  creations. 

f"~     Sometimes  the  creations  of  genius  come  to  the  artist  or 
I  author  in  a  flash — "inspired,"  as  we  say.    It  is  the  common 
I   belief  that  in  such  "inspired  moments"  genius  transcends 
1    the  ordinary  world  of  experience  and  catches  glimpses  of  a 
higher  reality.    However  this  may  appeal  to   the  popular 
mind,  it  will  not  stand  the  test  of  sober  analysis.    No  crea- 
tion of  genius  can  be  found  that  does  not  have  a  broad  back- 
ground of  real  experience  behind  it.    The  great  "poem  does 
not  sing  itself,"  but  springs  up  out  of  a  ripe  and  extended 
experience,  even  though  it  may  suddenly  appear  as  a  happy 
thought  or  inspiration.    It  is  not  a  transcendental  importa- 
tion, but  an  idealized  and  transformed  mundane  experience 
awaiting  just  the  right  combination  of  circumstances  to  call 
it  forth. 

•*-  On  the  other  hand,  many  great  productions  of  art  and 
literature  are  plainly  the  result  of  prolonged  and  intense  con- 
scious effort.  They  are  forged  by  an  indomitable  will  out  of 
the  raw  materials  of  experience.  With  respect  to  the  source 
from  which  these  two  phases  of  constructive  imagination 
draw  their  material  there  is  no  difference  between  them. 
They  differ  only  in  the  manner  in  which  they  function,  one 
easily,  without  effort  or  evident  plan,  and  the  other  with 
intense  effort  and  purpose.  But  both  draw  their  material 
from  the  same  source — experience. 

In  fancy,  the  restraint  of  purpose  or  plan  and  the  con- 
trolling influence  of  real  events  are  in  abeyance.    Imagina-       \ 
tion  here  has  a  free  rein,  creating  for  us  a  fantastic  world  of  A 
giants  and  pygmies,  fairies  and  demons,  harpies  and  griffins^    <jk 
or  giving  us  an  imaginary  existence  in  day-dreaming  and  *^ 
reverie,  where  we  can  build  our  air-castles  to  our  heart's  con- 


IMAGINATION  265 

tent  and  give  expression  to  all  manner  of  unrealities.  Here 
are  exhibited  the  freest  images  of  the  mind.  Yet  even  these 
creations  of  imagination  show  their  dependence  upon  real 
experiences.  The  fairy  or  the  griffin  must  needs  be  formed 
in  the  moulds  of  past  experiences.  The  relation  of  fancy  to 
constructive  imagination  is  really  one  of  degree,  depending 
upon  the  amount  of  control  involved  in  the  imaginary  output. 
The  line  between  them  is  not  sharply  marked  at  times,  as  is 
illustrated  by  such  creations  as  "Alice  in  Wonderland"  or 
"Gulliver's  Travels."  In  both  cases  the  products  of  fancy 
are  subordinated  to  a  definite  constructive  plan. 

The  rise  in  consciousness  of  these  free  and  uncontrolled 
images  is  facilitated,  and  their  vividness  increased,  by  the 
use  of  certain  drugs.  In  hashish  intoxication,  the  flight  of 
grotesque  images  becomes  very  marked.1  Opium  and  alcohol 
also  loosen  the  normal  control  of  images  and  start  unusual 
"flights  of  fancy,"  sometimes  even  causing  hallucinations. 

The  image  of  productive  imagination  is  a  new  experience 
— respresenting  something  that  has  not  happened  to  us  be- 
fore. Productive  images  have  the  feeling  of  newness.  There- 
fore the  content  attracts  and  holds  the  attention  more  vividly 
than  do  the  contents  of  reproductive  images.  Thejjroductive 
image  is  filled  outjnore  completely,  and  is  more  often  an  end 
in  Itself,  i.  e^  thought  of  foots  jownjake;  while  the  reproduc- 
tive  images,  especially  images  of  memory,  are  used  to  sym- 
bolize  former  experiences  and  arp  nr><-  in  fhpmqplvpi  nn  nnd 


of  consagjisness.  As  we  become  more  and  more  familiar 
with  objects  or  events,  mental  images  which  at  first  merely 
copy  or  reproduce  them  tend  more  and  more  to  symbolize 
the  objects  or  events,  and  in  so  doing  lose  much  of  their 
sensory  content.  Reproductive  images,  in  this  way,  romp 
to Jbe  the  vehicles  of  meaning^  i.  e.,  stand  for  somethingJie- 
sjdes  themselves.^  After  a  number  of  objects  or  events  of 
the  same  kind  are  experienced,  we  do  not,  when  we  wish  to 
think  of  them,  revive  each  and  every  one  in  terms  of  their 

1  See  James:  "Principles  of  Psychology,"  vol.  II,  p.  121. 


266  PSYCHOLOGY 

sensory  contents.  We  shorten  the  process  of  thinking  by 
allowing  a  single  image  to  stand  for  all  the  individual  images. 
In  this  way  reproductive  images  begin  to  carry  meaning  and 
so  to  take  part  in  a  larger  process — the  process  of  conception — 
in  which  we  think  our  past  experiences  not  a£  single  indi- 
r"  vidual  experiences,  as  we  do  in  reproductive  imagination,  but 
in  classes,  or  groups  of  experience.  For  instance,  instead  of 
calling  up  one  by  one  the  image  of  every  horse  that  we  have 
seen,  we  are  able  by  means  of  the  concept  to  consolidate  all 
these  single  past  experiences  into  one  thought.  A  single 
image  can  then  stand  for  all  horses.  But  a  single  image 
cannot  reproduce  the  sensory  content  of  all  past  experiences 
with  horses,  nor  as  a  symbol  of  them  does  it  need  to  do  so. 
For  in  the  larger  movements  of  thought  attention  is  with- 
drawn from  the  image  as  sensory  content  and  placed  upon  its 
meaning.  The  image,  in  this  case,  instead  of  reproducing  a 
single  past  experience  in  all  its  sensory  details,  symbolizes  all 
past  experiences  of  the  same  kind.  The  reproductive  image, 
therefore,  undergoes  a  transformation  in  its  function.  At 
first  it  reproduces  the  sensory  content  of  a  given  experience. 
Later  the  image  may  be  used  to  symbolize  all  experiences 
that  belong  to  the  same  class,  and  in  so  doing  it  drops  into 
the  background  of  consciousness,  because  attention  shifts 
from  the  image  to  its  meanings. 

The  productive  image,  on  the  other  hand,  just  because  it 
is  in  itself  a  new  experience  and  cannot  be  used  to  symbolize 
familiar  past  experience,  is  oftentimes  less  vague  and  sketchy 
and  more  stable  in  sensory  content  than  the  reproductive 
image. 

Types  of  Imagination. — We  have  seen  that  the  content  of 
imagination  is  the  same  kind  of  mental  stuff  as  that  of  sen- 
sation. Imagination  may  be  carried  on  in  terms  of  any  one 
•  or  all  of  the  senses.  Our  images,  therefore,  may  be  visual, 
auditory,  kinaesthetic,  tactual,  gustatory,  or  olfactory.  In 
recalling  a  past  or  imagining  a  new  scene,  we  may  mentally 
picture  the  forms  and  colors,  mentally  hear  the  sounds,  or 


IMAGINATION  267 

feel  the  actions,  etc.,  which  were  present  in  the  original  ex- 
perience. Some  individuals  have  fallen  into  the  habit  of 
using  one  kind  of  sense  material  more  predominantly  than 
any  other  in  their  mental  imagery.  This  gives  rise  to  types 
of  imagination,  according  to  the  sensory  content  which  is 
used  in  thinking.  Some  persons  recall  in  terms  of  vision, 
others  in  auditory  terms,  and  others  in  motor  images,  etc. 

Visual  Type.  —  The  visual  type  is  most  common.  Past 
experiences  and  creations  of  imagination  come  to  us  in  visual 
sensory  material.  We  see  the  past  and  construct  the  future 
in  the  "mind's  eye"  so  to  speak.  Sculptors,  painters,  and 
architects  are  largely  visualizers,  although  to  be  a  good  artist 
does  not  mean  that  one  must  image  in  terms  of  vision.  Kin- 
aesthetic  or  motor  images  may  be  substituted  for  the  visual. 
Gal  ton  found  in  his  investigation  of  imagery1  a  number  of 
artists  of  note  who  were  not  of  the  visual  type.  Professor 
James  says  of  himself:  "I  am  myself  a  good  draftsman  and 
have  a  lively  interest  in  pictures,  statues,  architecture,  and 
decoration,  and  a  keen  sensibility  to  artistic  efforts.  But  I 
am  an  extremely  poor  visualizer,  and  find  myself  often  unable 
to  reproduce  in  my  mind's  eye  pictures  which  I  have  carefully 
examined."2 

Auditory  Type.  —  As  a  rule,  musicians  are  of  the  auditory 
type  of  imagination.  Beethoven  composed  his  symphonies 
after  losing  his  hearing.  A  good  illustration  of  the  auditory 
type  is  furnished  by  the  playwriter,  Legouve,  who  said  to 
his  friend  Scribe:  "When  I  write  a  scene,  I  hear  and  you  see. 
At  each  phrase  which  I  write,  the  voice  of  the  person  speak- 
ing strikes  my  ear.  The  diverse  intonations  of  the  actors 
sound  under  my  pen  as  the  words  appear  on  my  paper." 
It  verVL  often  occurs  that  the  auditory  type  is  rnmhineH 

type.  Persons  who  image  the 


sound  of  the  words  also  image  the  movements  of  their  enun- 
ciation. 

1  "Inquiries  into  Human  Faculty,"  p.  84. 

2  "Principles  of  Psychology,"  vol.  II,  p.  53. 


268 


PSYCHOLOGY 


•y 


Motor  Type. — Occasionally  an  individual  may  be  found 
whose  imagination  consists  largely  in  images  of  movement. 
They  habitually  recall  past  experiences,  or  imagine  future 
events,  in  terms  of  the  movements  contained  in  them.  In 
recalling  words,  they  image  the  movements  of  articulation. 
They  think  of  objects  in  terms  of  the  eye-movements  required 
in  perceiving  them.  The  student  may  observe  the  tendency 
to  image  the  movements  of  articulation  by  thinking  such 
words  as  "bubble,"  "toddle,"  "pepper,"  and  observing  the 
resultant  motor  images. 

These  three  types,  visual,  auditory,  and  motor,  are  the 
only  well-defined  types.  Tactual,  gustatory,  and  olfactory 
images  are  possible,  but  they  hardly  ever  usurp  the  chief 
place  in  the  imagination  of  normal  individuals.  The  case  of 
Zola,  the  writer,  is  interesting  because  of  its  rarity.  He 
could  recall  and  image  odors  more  distinctly  and  more  easily 
than  colors.  Nearly  every  object  had,  when  he  recalled  it, 
a  distinctive  odor.  When  he  thought  of  certain  streets,  cities, 
or  even  the  seasons  of  the  year,  definite  images  of  smell 
arose  in  connection  with  the  thought  of  them. 

The  explanation  of  these  types  of  imagination  will  prob- 
ably be  found  in  the  fact  that  some  individuals  form  the 
habit  of  thinking  in  terms  of  some  one  sense  to  the  exclusion 
of  the  others.  A  predominating  interest  of  some  kind  may 
determine  and  fix  the  habit.  How  far  heredity  may  be  in- 
volved as  a  factor  we  do  not  yet  know. 

A  curious  error  has  sometimes  been  made  in  applying  the 
psychology  of  the  types  of  imagination  to  education.  It  has 
been  suggested  that  the  "eye-minded"  child  should  be  taught 
largely  through  the  eyes,  and  the  "ear-minded"  through  the 
ears.  Aside  from  the  general  principle  that  the  young  should 
receive  training  in  just  those  abilities  in  which  they  are  lack- 
ing (and  so  if  a  child  shows  inability  in  visual  imagery,  he 
should  for  that  reason  be  given  opportunity  to  develop  it  by 
supplying  him  with  sensory  visual  material) — aside  from  this 
consideration,  there  is  the  further  psychological  fact  that  a 


IMAGINATION  269 

child  who  is  lacking  in  visual  imagery  may  possess  an  excel- 
lent visual  perception,  so  that  he  is  able  to  make  accurate 
discriminations  in  everything  that  he  actually  sees.     He  may, 
therefore,  be  able  to  get  more  through  the  eye  than  through 
the  ear  in  actual  'presentation.     But  what  he  gets  through 
the  eye  he  may  translate  into  auditory  terms,  retaining,  and 
recalling   his   acquisitions  in  these  terms.     The  conditions. 
which  make  accurate  perception  in  the  presentation  of  a  givenlx 
sense  possible  may  not  accompany  accurate  imagery  in  thatyj 
sense.     Imagery  of  the  material  presented  may  take 
easily  in  terms  of  another  sense.  ~XA*V  ****** 


*J*"^ji£frA    .. 
oflmagesx\**/ 


Mixed  Types.  —  In  most  individuals,  the  contents  oflmage 
are  drawn  from  all  the  senses  —  sometimes  from  one  and 
sometimes  from  another.  One  may  have  visual  imagination 
for  one  kind  of  experience,  and  auditory  or  motor  for  an- 
other. Visual,  auditory,  and  kinaesthetic  sensations  furnish 
most  of  the  content  of  imagination.  Gustatory,  olfactory, 
and  tactile  sensations  are  represented  less  often.  Probably 
no  person  has  one  type  of  imagination  alone. 

Methods  of  Determining  the  Types  of  Imagination.  — 
Francis  Galton's  statistical  study  of  the  imagination  was  the 
first  important  attempt  to  determine  the  nature  of  imagina- 
tion in  individuals.1  He  prepared  a  list  of  questions  about 
mental  images,  which  he  required  a  large  number  of  persons 
to  answer.  In  each  case  he  relied  upon  the  direct  self-obser- 
vation of  his  subjects.  By  recalling  certain  scenes  or  objects, 
we  can  usually  determine  by  careful  observation,  the  types  of 
our  mental  images.  However,  more  objective  methods  have 
been  used  since  Galton's  time. 

One  simple  way  of  determining  whether  a  subject  is  visual 
or  auditory  in  his  imagery  is  to  require  him  to  write  as  rapidly 
as  possible  a  list  of  objects  that  are  characterized  by  well- 
marked  colors.  Let  him  continue  to  write  for  five  minutes. 
Then  stop  him  and  after  he  has  rested  for  some  minutes 
require  him  to  write  a  list  of  words  characterized  by  sounds, 
1  "Inquiries  into  Human  Faculty." 


x/ 


270  PSYCHOLOGY 

allowing  him  the  same  length  of  time.  The  visual  type  will 
write  more  names  of  objects  characterized  by  color,  while 
the  auditory  type  will  write  more  names  of  objects  character- 
ized by  sounds. 

The  learning  method  has  also  been  used  for  this  purpose. 
For  instance,  make  several  lists  of  letters,  twelve  in  each. 
Have  the  subject  read  one  of  the  lists,  not  allowing  him  to 
pronounce  the  letters  to  himself.  See  that  the  only  impression 
he  receives  is  the  visual  one.  Find  out  how  many  letters 
he  has  learned  of  this  list  after  reading  it  once.  Then  read 
another  list  of  equal  difficulty  to  the  subject  and  determine 
how  many  of  this  list  he  can  remember.  Repeat  each  ex- 
periment ten  times,  taking  careful  note  of  the  number  and 
character  of  the  errors.  If  the  subject  learns  a  much  larger 
number  of  the  lists  he  reads  himself  than  of  those  that  are 
read  to  him,  he  is  visual  in  type.  If,  on  the  other  hand,  he 
learns  more  of  the  lists  read  to  him,  he  is  auditory  in  type. 
The  nature  of  the  errors  is  also  an  indication  of  the  type  of 
imagery  employed.  The  visual  type  will  confuse  the  letters 
of  like  appearance,  c  and  e,  p  and  q,  u  and  v.  The  auditory 
type  confuse  letters  of  like  sound,  b  and  d  and  p. 

The  literary  productions  of  writers  may  be  analyzed  and 
the  types  of  images  employed  determined.  Thus  Miss  Cal- 
kins1 quotes  a  poem  from  the  blind  poet,  Philip  Marston,  and 
shows  that  he  uses  only  one  color  image  in  the  whole  poem, 
while  images  of  sound  and  odor  are  plentiful. 

Imagery  in  Synaesthesia. — Cases  of  synaesthesia  furnish 
interesting  instances  of  various  kinds  of  imagery.  Synsesthe- 
sia  is  the  term  which  we  give  to  those  forms  of  associations 
which  some  individuals  experience,  in  which  the  presentation 
of  an  object  is  accompanied  by  mental  images  in  another 
sense.  For  instance,  some  persons  image  different  colors 
when  they  hear  or  think  of  tones.  The  different  tones  have 
them  certain  definite  colors.  The  high  tones  have 
right  colors  and  the  low  tones  the  darker  colors.  The  days 

1  "Introduction  to  Psychology,"  p.  191. 


IMAGINATION  271 

of  the  week,  the  months,  the  seasons  of  the  year,  also  arouse, 
in  some  cases,  images  of  color.  Even  the  letters  of  the  al- 
phabet, names  of  objects,  or  proper  names,  may  be  associated 
with  images  of  color.  Galton1  reports  a  case  in  which  the 
vowels  were  imaged  in  colors  while  the  consonants  were  al- 
ways purplish-black.  This  subject  says:  "For  example,  in 
the  word  Tuesday,  when  I  think  of  each  letter  separately,  the 
consonants  are  purplish-black,  u  is  a  light  dove-color,  e  is  a 
pale  emerald  green,  and  a  is  yellow;  but  when  I  think  of  the 
whole  word  together,  the  first  part  is  light  gray-green  and 
the  latter  part  is  yellow."  This  form  of  synaesthesia,  the 
arousal  of  concomitant  color  images,  has  been  termed  chrom- 
(Bsthesia. 

Another  instance  of  synaesthesia  is  the  "number-form." 
Some  individuals  always  image  the  digits  and  lower  numbers 
(usually  not  beyond  one  hundred)  as  occupying  a  definite 
position  in  space  and  arranged  in  a  certain  form.  The  hours 
of  the  day,  the  days  of  the  week,  and  the  months  of  the  year 
may  also  have  a  definite  imaginary  arrangement  which  is 
always  constant  for  the  same  individual,  but  for  different 
individuals  the  forms  are  never  the  same.  These  number- 
forms  will  sometimes  be  found  in  several  members  of  the 
same  family.  Baldwin  has  published  number-forms  of  five 
different  members  of  the  same  family2  and  reports  another 
case  of  three  in  a  family  who  have  them.  He  is  of  the  opinion 
that  they  are  hereditary  in  origin.  Other  authorities  think 
that  they  are  due  to  fixed  associations  formed  between  num- 
bers and  spatial  positions. 

Concrete  and  Symbolic  Imagination. — So  far  we  have 
considered  images  only  as  imitating  or  reproducing  the  sen- 
sory content  of  former  experiences.  This  is  concrete  imagina- 
tion. '  If  I  imagine  the  appearance  of  an  object,  I  have  a 
concrete  visual  image;  if  I  recall  the  sound  of  a  bell,  the 
image  is  concrete;  if  I  imagine  the  feeling  of  velvet,  the  image 

1  "Inquiries  into  Human  Faculty,"  p.  149. 

4 Baldwin's  "Dictionary  of  Philosophy  and  Psychology,"  pp.  654-5. 


272  PSYCHOLOGY 

is  also  concrete.  So  all  imagination  which  brings  back  the 
sensory  qualities  of  experiences  is  concrete. 

If,  on  the  other  hand,  I  recall  the  word  or  other  sign 
which  stands  for  an  experience  without  reviving  the  sensory 
experience  itself,  my  imagination  is  symbolic.  For  instance, 
if  I  remember  that  a  certain  gown  was  red,  I  may  merely 
recall  the  word  and  not  the  visual  appearance.  There  is  a 
constant  tendency,  as  we  become  more  and  more  proficient 
in  the  use  of  language,  for  the  concrete  sensory  material  of 
our  images  to  be  replaced  bv  word  images  Cyprha]  imagery V 
These  word  images  are  either  auditory  images  of  the  words 
as  heard  or  motor  images  of  throat  movements  in  articula- 
tion, or  visual  images  of  the  words  as  printed  or  written. 
The  blind  may  have  tactual  word  images  as  well  as  auditory. 

Some  persons  mentally  picture  the  form  of  the  word 
which  represents  their  experiences;  others  hear  words  as 
though  they  were  spoken  by  themselves  or  by  some  one  else; 
while  others  image  the  feeling  of  the  word  in  the  throat  and 
lips.  Victor  Egger  reports  "that  he  hears  his  thoughts  as  it 
were  in  auditory  word  images."  Tennyson,  whose  verse  is 
noted  for  its  rhythmic  harmony,  must  have  had  this  form  of 
verbal  imagery  very  highly  developed.  Still  others  image  the 
words  expressing  their  thoughts  in  terms  of  movements  in 
throat  and  lips.  Doctor  Strieker,  in  his  monograph  on  speech 
images  says  that  he^els  his  thoughts  in  mentally  half-sup- 
pressed whispersfHot  heard  but  articulated  mentally.  In  this 
verbal-motor  type  of  imagery,  there  is  a  strong  tendency  for 
the  images  of  articulatory  movements  to  bring  about  the 
^  jf\!  .movements  themselves,  so  that  those  who  possess  this  form 
.  Jr  •/  of  imagery  are  apt  to  whisper  or  talk  to  themselves. 

Most  of  us  have  noticed  that  as  we  grow  older  we  lose  the 
ability  to  recall  the  sensory  contents  of  our  experiences.  The 
"look"  and  "sound"  of  things  will  not  come  back  to  us  as 
vividly  and  accurately  as  they  did  when  we  were  children. 
We  have  attributed  this  to  a  loss  of  imagination.  It  is  due 
not  to  a  loss  of  imagination,  but  to  a  change  in  the  form  of 


IMAGINATION  .  273 

imagination.    The  original  and  primary  concrete  image  has 
been  displaced  by  the  word  or  the  symbolic  image.     Our 
whole  education  is  largely  a  training  in  translating  our  ex- 
periences into  language  symbols.     We  could  jnake  little  prog-t 
ress,  if  we  were_j)bliged  to  think  o^  experiences^  in_their\ 
original  concreteness;  so  we  use  language  to  symbolize  them.j 
As  we  increase  our  facility  in  thinkmg7we  nnd  that  we  can- 
not  stop  to  image  all  of  the  concrete  "stuff"  of  experience. 
This  would  be  a  hindrance  to  abstract  thought.     We  know 
that  the  American  flag  is  made  of  stripes  of  red  and  white, 
and  has  a  field  of  blue,  etc.,  but  we  do  not  now  have  to  pic- 
ture these  forms  and  colors.     We  let  the  words  stand  for 
them  without  imaging  the  concrete  realities.     Galton  found 
that  many  men  of  science  were  practically  without  concrete 
imagery,  and  concludes   "that  an  overready  perception  of, 
sharp  mental  pictures  is  antagonistic  to  the  acquirement  of  j 
habits  of  highly  generalized  and  abstract  thought." 

When  images  first  began  to  play  a  part  in  the  mental  life 
of  the  child,  they  were  necessarily  copies  of  the  concrete 
qualities  of  objects.  They  were  vivid  and  detailed  repro- 
ductions of  sensations  and  perceptions.  But  later  when  he 
became  familiar  with  the  word  symbols  which  stand  for  the 
qualities  of  the  sensation,  he  gradually  substituted  the  word 
symbol  for  the  experience  itself  when  he  wished  to  think  of 
it.  In  some  cases  verbal  imagery  is  all  that  is  retained  of  our 
past  experiences.  Thus  I  may  remember  that  a  certain  man 
is  tall  and  has  red  hair,  but  I  may  not  be  able  to  form  any 
concrete  image  of  him  whatsoever.  Indeed,  as  our  education 
proceeds,  we  come  more  and  more  to  rely  on  words  rather 
than  on  the  imagery  of  concrete  objects  in  recalling  the  past 
or  planning  the  future. 

The  oqnpifl  tppofltir  tendency  of  certain  words  is  an  in- 
teresting fact  in  me  substitution  of  language  symbols  for  the 
concrete  experiences.  Such  words  as  "hiss,"  "rumble," 
"crack,"  "swish/l  "buzz"  attempt  to  imitate  and  preserve 
the  auditory  sensory  qualities  for  which  they  stand.  The 


274 


PSYCHOLOGY 


child  calls  the  dog  " bow- wow"  for  the  same  reason.  The 
imitation  in  the  symbol  of  some  sensory  quality  of  the  thing 
symbolized  is  a  survival  of  concrete  imagination. 

Image  and  Idea. — The  term  "idea  "  has  a  number  of 
eanings  which  are  in  current  popular  use.  Even  in  the 
iterature  of  psychology  there  is  no  uniform  usage.  In  the 
old  traditional  doctrine  of  the  association  of  ideas,  an  idea 
is  some  definite  permanent  meaning  looked  upon  as  a  psychic 
existence  with  powers  of  attraction  and  repulsion,  analogous 
to  the  physical  atom.  Some  ideas  attract  each  other  and 
flock  together  in  the  mind,  while  others  repel  each  other. 
A  more  modern  usage  makes  idea  practically  synonymous 
with  concept  Idea,  accordingly,  is  an  image_of  an_  object 
plus  the^bbject's  meaning.  The  idea  of  a  horse  is  the  horse- 
image  together  with  the  horse-meaning.  In  this  case,  while 
the  idea  includes  both  the  image  and  the  meaning,  it  em- 
phasizes the  meaning  rather  than  the  sensory  content  of  the 
image.  In  an  idea  we  attend  to  the  meaning  and  not  to  the 
image. 

A  more  satisfactory  use  of  the  term  and  one  agreed  upon 
by  a  number  of  psychologists  is  that  which  makes  idea  "the^ 
reproduction,   witfr    a    mnr^   QJ   1p^  arlpqnqfp  imager   of  aji 


ojjject  jngj;  artually  present  to  the  senses."1  An _ idea  is, 
therefore,  the  reproduction  of  a  perception^  I  have  an  idea 
of  my  dog  when  I  recall  his  appearance  through  reproductive 
» images.  Ideational  processes,  then,  are  processes  of  mental 
Reproduction  hi  which  there js_a.  succession  of  ideas. 

Training  of  Imagination. — Since  imagination,  both  repro- 
ductive and  productive,  draws  its  content  from  original  sen- 
sory experiences,  it  follows  that  the  beginning  of  imagination 
lies  in  accurate  sensory  acquaintance  with  things  as  they 
really  are.  The  accuracy  and  vividness  of  reproductive 
images  depend  upon  the  accuracy  and  the  vividness  of  the 
percept.  Beyond  this  it  may  be  cultivated  in  any  particular 

1  Definition  of  idea  given  in  Baldwin's  "Dictionary  of  Philosophy  and 
Psychology." 


IMAGINATION  275 

line  to  almost  any  extent  by  continual  practice.  The  won- 
derful visual  imagery  of  Pillsbury,  the  chess-player,  who  was 
able,  blindfolded,  to  play  twenty  games  of  chess,  requiring 
him  to  image  and  keep  in  mind  all  the  combinations  of  the 
chessmen  in  these  twenty  games,  is  due  to  practice  in  doing 
just  that  thing.  It  should  be  noted,  however,  that  his  ability 
to  image  other  than  chess-board  situations  .was  not  above 
the  average.  In  the  first  place,  he  made  himself  perfectly 
familiar  with  the  chess-board.  Then  practice  in  imagining 
the  different  positions  of  the  men  on  the  board  made  it  un- 
necessary for  him  to  have  the  actual  board  before  him.  While 
such  overtraining  of  the  imagination  may  be  valuable  for 
certain  specialized  purposes,  it  is  doubtful  as  a  general  edu- 
cational procedure.  The  imagination  can  and  should  be 
cultivated,  but  not  on  any  special  kind  of  material  to  the 
exclusion  of  all  others. 

Imagination  as  a  Means  of  Supplementing  the  Present. — 
It  is  unnecessary  to  dwell  upon  the  fact  that  imagination 
enriches  the  presentations  of  the  present  moment.  What  is 
actually  given  in  sensory  content  is  poor,  indeed,  when  com- 
pared with  the  wealth  of  material  poured  in  by  the  imagina- 
tion. The  present  is  supplemented  not  only  by  the  past 
through  reproductive  imagination,  but  it  is  modified  by  the 
future  through  creative  imagination.  The  actual  and  the 
real  become  enlarged  by  the  ideal.  For  a  creature  without 
imagination  there  is  nothing  but  the  sensory  bareness  of  the 
actual  present  moment.  For  him  there  would  be  no  revivals 
of  the  actual  past,  no  constructive  images  of  science,  litera- 
ture, and  art,  no  fairy-tales,  and  no  myths. 

Imagination  and  Behavior. — In  the  first  stages  of  volun- 
tarily formed  motor  habits,  the  image  of  movement  precedes 
the  movement  itself.  For  instance,  before  picking  up  my 
pen,  I  may  image  the  finger  and  arm  movements  necessary 
to  perform  the  act.  Or  before  pronouncing  a  word,  I  may 
form  the  images  of  the  movements  required  in  articulation. 
When  habits  of  action  are  once  formed,  images  of,  almost  any 


276  PSYCHOLOGY 

kind  may  instigate  an  action.  The  image  of  the  pen  in  my 
hand,  or  the  image  of  the  sound  of  the  word  may  precede  the 
proper  movements  of  execution.  So  the  image  is  a  means 
of  controlling  our  behavior.  The  man  who  successfully  car- 
ries through  a  great  activity,  whether  it  is  a  military  cam- 
paign or  a  business  venture,  is  the  man  who  can  image  his 
actions  and  their  results — in  other  words,  the  man  who  can 
imagine  the  future  as  different  from  the  present.  The  man 
of  action,  the  captain  of  industry,  is  quite  as  much  the  man 
of  imagination  as  the  artist  or  the  author. 

There  is  a  general  belief  that  it  does  not  matter  what  kind 
of  images  one  allows  to  take  form  in  his  thoughts  so  long  as 
he  does  not  commit  the  overt  act.  Psychology  cannot  con- 
cur in  this  belief .  We  have  already  seen  that  the  kinaesthetic 
images — the  images  of  movement — possess  a  strong  tendency 
to  bring  about  the  actual  movement  itself.  No  one  can 
allow  the  image  of  an  act  of  any  kind  to  rest  in  his  thoughts 
without  paving  the  way  to  the  actual  act.  Sooner  or  later 
forms  of  behavior  which  one  continues  to  image  will  become 
a  reality. 

Because  of  this  tendency  of  images  to  pass  over  into  overt 
acts,  we  may  say,  with  certain  modifications,  that  we  actually 
create  our  futures  through  the  kind  of  images  we  entertain. 


CHAPTER  XII 
ASSOCIATION 

Although  we  have  already  referred  to  the  associative  con- 
nections which  bind  experiences  together,  we  must  here  con- 
sider more  systematically  this  tendency  of  conscious  states 
to  be  associated  into  complexes  and  groups  which  hang  to- 
gether with  varying  degrees  of  cohesion.  It  is  a  matter  of 
common  observation  that  mental  states  are  held  together 
into  units,  groups,  and  constellations,  so  that  if  one  member 
appears  in  consciousness,  the  other  members  follow.1  It  is 
evident  that  some  mental  states  are  intimately  bound  to- 
gether, while  others  are  connected  more  loosely.  The  thought 
"2  times  2"  is  always  followed  by  the  thought  "4";  the  word 
"honesty"  is  less  closely  connected  with  "is  the  best  policy," 
while  the  connection  between  the  thought  of  a  circle  and  the 
thought  of  immortality  is  still  less  intimate;  nevertheless  there 
is  a  connection. 

These  connections  are  acquired  in  the  course  of  experience 
and  serve  to  hold  the  component  parts  of  our  mental  life  to- 
gether. Without  these  connections,  there  could  be  no  such 
thing  as  thinking,  unless  a  mere  jumble  of  mental  states 
could  be  so  named.  If  a  given  mental  content  were  just  as 
liable  to  call  up  one  thought  as  another,  there  would  be  no 
coherence  of  thought.  In^e^jJ^ie__forniation  of  associative 
connections  is  the  backbone  of  the  organization  of  conscious- 
ness. Education  is  really  the  process  of  forming  associative 

1  The  language  here  is,  of  course,  figurative.  When  one  member  of  a  group 
of  experiences  is  in  consciousness,  we  do  not,  like  some  of  the  old  associational- 
ists,  suppose  that  the  other  mental  states  of  the  group  are  actually  in  exis- 
tence outside  of  our  consciousness,  awaiting  their  turn  to  come  in.  We  mean 
by  association  only  the  possibility  of  one  mental  state  being  revived  when 
another  is  actually  in  consciousness. 


278 


PSYCHOLOGY 


connections.  Our  formal  educational  program  puts  together 
the  'things  that  we  think  should  go  together  in  the  child's 
mind,  and  presents  them  to  the  child  in  organized  systems  of 
knowledge.  We  know  that  the  mental  connections  thus 
formed  will  dominate  his  later  thinking  and  acting.  With 
the  visual  appearance  of  the  letters  "c-a-t,"  we  associate  the 
sound  "cat";  with  "nine  times  nine"  we  connect  "81";  with 
the  idea  of  "first  President"  we  put  the  idea  of  "Washington," 
etc.  As  the  child  progresses  along  the  educational  route,  we 
attempt  to  fix  in  his  mind  what  we  consider  are  the  proper 
mental  connections  in  science,  literature,  art,  and  all  the 
other  disciplines  of  knowledge.  At  the  same  time  the  child, 
in  his  daily  contact  with  life  in  the  home,  on  the  street,  with 
his  companions,  is  forming  his  own  mental  connections.  So 
gradually  his  mental  content  settles  down  into  connected 
systems.  What  he  thinks  and  what  he  does  in  any  given 
situation  depends  upon  the  nature  of  the  mental  connections 
he  has  formed  in  the  past.  Even  what  we  commonly  call 
character  is  a  matter  of  mental  connections.  The  difference 
between  the  pessimist  and  the  optimist,  the  rogue  and  the 
honest  man,  the  silly  dandy  and  the  man  of  brains,  lies  in 
the  nature  of  their  mental  connections.  In  every  phase  of 
mental  life,  from  the  association  of  simple  sensations  to  form 
a  perception,  to  the  union  of  ideas  and  desires  to  form  our 
ideals,  associative  connections  are  determining  factors. 

Formation  of  Associations. — Association*  a,rf  arqm'rp(l_ 
mental  connections.  In  attention,  certain  parts,  phases, 
aspects,  or  ieatures  of  a  total  object  or  situation  fall  succes- 
sively or  simultaneously  within  the  focus  of  consciousness. 
When  later  any  part,  aspect,  or  feature  of  the  object  or  situ- 
ation is  presented  or  is  thought  of,  the  other  aspects  also 
appear  in  consciousness.  This  is  the  fundamental  fact  of 
association.  On  hearing  the  noise  of  a  street-car,  which  I 
cannot  see,  the  visual  image  of  the  car  arises  in  my  conscious- 
ness because  the  auditory  and  visual  sensations  have  been 
associated  together  in  the  actual  experience  of  the  car. 


Motor  Connections. — -There  is  a  large  group  of  associations 
that  have  not  always  been  included  in  discussions  of  associa- 
tion forthe  reason  that  one  of  the  terms  of  the  association  is 
not  a  mental  state.  I  refer  to  the  connections  between  states 
of  consciousness  and  motor  reactions.  Here  we  have  the 
whole  field  of  motor  habit  formation  before  us.  Certain  acts 
become  connected  with  certain  mental  states,  so  that  the  acts 
are  always  called  out  by  the  mental  states.  The  sight  of  my 
sn  on  the  floor  prompts  me  to  pick  it  up.  The  soldier  hears 
the  command  "Halt!"  and  stops  short.  The  telegraph 
operator  sees  a  word  and  his  hand  immediately  executes  a 
number  of  dots  and  dashes.  All  these  are  the  result  of  ac- 
quired connections  which  have  been  formed  in  previous  asso- 
ciations.1 What  happens  in  such  cases  is  that  the  sensory 
brain  centres  discharge  directly  into  the  motor  centres  and 
pathways. 

Mental  Connections. — The  purely  mental  connections 
make  up  a  large  and  varied  group  of  associations.  The  clos- 
est associations  are  those  between  the  different  sensations 
which  enter  into  a  perception.  Thus  the  color,  form,  odor, 
and  tactual  qualities  of  the  rose  form  a  .compact  and  unitary. 
group  of  experiences.  If  the  velvety  softness  of  the  petals  is 
experienced  on  the  finger-tips,  the  other  sensory  qualities  of 
the  rose  spring  into  consciousness  as  images,  and  we  get  an 
idea  of  the  rose  as  a  whole.  This  process  of  recall  we  have 
named  complication. 

In  the  association  of  different  perceptions,  the  terms  of 
the  association  are  not  so  closely  combined  as  is  the  case  in 
the  union  of  sensations  in  the  perception.  The  percepts 
stand  apart  in  the  combination  and  preserve  their  identity. 
They  are,  however,  bound  together  by  certain  relations. 

1  Connections  may  also  be  acquired  between  one  motor  reaction  and  an- 
other. This  is  manifested  in  the  so-called  "chained  reactions."  A  habit  com- 
posed of  several  individual  reactions  following  each  other  may,  if  started,  run 
itself  off,  without  conscious  direction.  The  first  reaction  arouses  the  second, 
the  second  the  third,  and  so  on  until  the  end.  Thus  if  the  first  bar  of  a  familiar 
piece  of  music  is  consciously  executed,  the  rest  will  play  itself,  as  it  were. 


I 


A- 

280  0V  ^AT    JK  -^        PSYCHOLOGY 


^ 

- 


These  relations  may  be  established  either  by  the  fact  of  simul- 
taneous and  successive  presentations^  or  by  the  fact  of  simi- 
larity, contrast,  cause  and 


Objects  or  events  that  are  presented  at  the  same 
time  acquire  an  associative  connection.  Likewise,  if  one 
object  or  event  follows  another,  the  two  become  tied  together 
in  a  more  or  less  effective  mental  union.  The  different  parts 
and  persons  in  the  scene  which  I  witness  as  I  pass  through  a 
workshop  are  associated  together  merely  because  they  are 
experienced  together.  Likewise,  the  different  events  and 
scenes  of  my  summer's  excursion  are  bound  together  because 
they  follow  each  other.  It  was  formerly  thought  that  imme- 
diate succession  was  necessary  for  the  formation  of  associa- 
tions, but  it  has  been  found  that  associative  ties  are  formed 
between  more  or  less  remote  members  of  a  series  of  events  or 
objects.  Each  member  of  the  series  becomes  linked  (in  a 
lessened  degree,  to  be  sure,  but  nevertheless  in  a  degree  capa- 
ble of  demonstration  experimentally)  to  the  member  which 
comes  next  but  one,  and  also  to  the  one  which  comes  next 
but  two,  etc.  The  associative  connections  decrease  in 
strength  as  the  members  become  more  and  more  remote. 
.This  indicates  that  associative  links  form  not  only  between 
the  members  serially,  but  that  there  is  a  tendency  for  suc- 
cessive presentations  to  form  into  a  group  in  which  any  one 
member  is  linked  to  all  the  other  members  as  well  as  to  the 

•B*^"^  ••••••••••••••••••••••••Ml  •"•"•••••••••^^^^^^ 

one  preceding  or  following  it. 

It  has  been  found  experimentally  that  the  arrangement 
of  individual  experiences  into  groups  or  higher  units  of  expe- 
rience serves  to  intensify  the  associative  connections  and 
weld  the  parts  more  firmly  together.  The  tendency  of  ex- 
periences to  form  into  higher  units  is  called  the  principle  of 
integration.  For  instance,  the  events  of  a  summeF  spent  in 
.Europe  are^  connected  serially  one  to  the  other.  But  the 
events  tend  to  form  into  units  of  experiences,  which  are  inte- 
grated into  higher  or  larger  units  than  any  single  event. 
The  German  scenes  and  events  form  what  we  have  called  a 


ASSOCIATION  281 

higher  unit.  The  French,  Italian,  and  English  experiences 
form  others.  What  happened  in  Germany  therefore  gets  a 
special  German  connection,  and  so  with  the  other  parts  of 
the  journey. 

We  may  sum  up  all  the  cases  of  association  so  far  men- 
tioned under  the  principle  of  contiguity.     Things  that  are  ex-  ^ 
perienced  together  or  thought  together  form  associative  con- 
nections. 

There  is  a  difference  between  associations  that  are  formed 
passively  through  mere  external  contiguity  and  those  that 
are  actively  formed  because  we  attend  to  the  logical  relation- 
ships which  exist  between  the  parts  of  our  experience.  The 
latter  are  much  more  permanent.  Mere  contiguity,  however, 
rarely  ever  works  alone  in  the  formation  of  associations. 
There  is  almost  always  some  thread  of  interest  or  some  rela- 
tionship which  ties  experiences  together.  The  most  impor- 
tant of  these  relationships  are  similarity,  contrast,  cause,  and 
effect.  Things  that  are  similar  or  contrast  sriarply,  or  are 
related  as  cause  and  effect,  attract  and  hold  the  attention 
when  they  are  presented.  They  are,  of  course,  experienced 
at  the  same  time,  also,  but  attention  actively  connects  them 
because  they  are  similar  or  because  they  contrast  or  stand  in 
the  relation  of  cause  and  effect.  There  are  many  other  rela- 
tionships that  bind  original  experiences  together.  Even  time 
and  space  relations  of  things  may  be  actively  noted,  and  for 
that  reason  aid  in  forming  associations. 

There  are  other  important  conditions  under  which  the 
principles  of  contiguity,  similarity,  etc.,  operate  in  the  forma- 
tion of  associative  connections.  For  instance,  the  presence 
of  a  Purpose  or  plan_m  the  mind  will  select  and  intensify  cer- 
tain parts  01  oin^a^erience,  and  so  control  the  formation  of 
associations.  Thus,  the  desire  or  purpose  to  remember  the 
names  of  the  voters  in  his  district  will  facilitate  the  formation 
of  name  associations  in  the  politician's  mind. 

Closely  related  to  purpose  in  controlling  the  formation  of 
associations  is  the  dominant  interest  in  the  mind  at  the  time. 


282  PSYCHOLOGY 

Mental  states  are  related  because  of  interests.     If  one  is  in- 
terested in  athletics,  athletic  scores  and  records  form  into  a 
closer  system  of  associative  connections  than  they  would  if 
•  &   the  interest  were  not  present. 

Experiences  that  are  vivid  and  clear  are  connected  more 

,.  closely  than  those  that  are  unclear.  This  is  really  a  repeti- 
tion of  the  statement  already  made  that  the  things  we  attend 
to  are  associated  together.  The  repetition  of  experiences 
intensifies  and  fixes  the  associative  bands  between  them. 
*"\  Everything  else  being  equal,  the  most  recently  formed 
associations  show  the  strongest  associative  ties.  As  associa- 
tive groups  become  older,  the  links  between  the  members 
rust  away,  so  to  speak.  The  experiences  of  yesterday  are 
more  firmly  associated  than  those  of  a  year  ago. 

An  interesting  fact  has  been  demonstrated  experimentally 
concerning  the  age  of  associative  connections.  Of  two  dif- 
ferent associative  connections  of  the  same  strength  at  any 
given  time,  the  older  is  more  permanent  (will  be  retained 
longer)  than  the  younger.  If,  for  instance,  I  am  now  equally 
conversant  with  two  groups  of  facts  of  the  same  difficulty, 
the  group  learned  last  wih1  fade  from  memory  first.  This 
holds  only  when  the  time  between  the  learning  of  the  two 
groups  is  long  enough  to  enable  the  associative  connections 
of  the  first  group  to  settle.  For  it  requires  a  certain  amount 
of  time  for  associations  to  fix  themselves.1  On  the  other  hand, 
,if  the  learning  of  the  one  set  of  associations  is  immediately 
followed  by  the  learning  of  another  set,  the  latter  sometimes 

••  weakens  the  former.     This  is  known  as  retroactive  inhibition. 

j  When,  after  giving  my  attention  to  one  group  of  facts,  I  turn 

immediately  to  another  group,  the  associations  formed  in  the 

Blatter  tend  to  inhibit  those  in  the  former.     Retroactive  inhi- 

.  *    "bition  is  most  active  when  the  material  of  the  two  groups  is 

of  the  same  nature.     Its  effect  disappears  after  a  time.     A 

f        familiar  illustration  is  furnished  in  every-day  life.     It  often 
happens  that  when  we  are  trying  to  recall  the  name  of  a  cer- 
1  This  is  known  as  Jost's  Law. 


ASSOCIATION  283 

tain  person  or  place  which  we  are  usually  able  to  do,  some 
one  will  suggest  an  incorrect  but  similar  name.  This  sugges- 
tion blocks  the  proper  association  and  we  find  ourselves 
unable  to  recall  the  familiar  name. 

The  maturing  or  ripening  of  associative  connections  is 
also  illustrated  in  common  experience.  If,  after  struggling 
for  some  time  with  apparently  little  success  to  learn  a  certain 
system  of  facts,  we  lay  aside  the  task  until  the  next  day,  we 
are  often  surprised  to  find  when  we  return  to  it  that  we  have 
really  mastered  it.  The  associations  have  become  fixed  over 
night. 

All  through  this  section  we  have  spoken  as  though  one 
mental  state  could  form  an  associative  connection  with  an- 
other mental  state.  Of  course,  the  student  understands  that 
this  is  only  a  figurative  way  of  stating  the  matter.  One 
mental  state  cannot  form  a  direct  connection  with  another 
mental  state.  The  connections  are  always  madej^ou^^p 
Jbrajn.  One  of  the  fundamental  presuppositions  of  this  book 
is  that  every  mental  state  has  a  physiological  brain  process 
back  of  it.  We  believe  that  when  two  mental  states  are  con- 
nected or  associated  the  real  connection  is  madejb]  thp  fftrrria- 
tion  ofjifiEKQU^iBiliw^vshfi^^gjijyi^jjgn^ie^in^^^fid.  The 
physiological  basis  for  association  we  shall  take  up  after  dis- 
cussing the  second  part  of  association — that  of  associative 
recall. 

Associative  Recall. — Since  the  time  of  Aristotle,  there  has 
been  a  great  deal  of  discussion  concerning  the  principle  of 
association.  He  called  attention  to  the  fact  that  when  we 
try  to  recall  anything  that  is  not  at  the  moment  in  the  mind 
we  think  of  something  that  is  similar,  or  opposite,  or  some- 
thing that  has  been  associated  with  it  in  time,  or  space.  The 
English  empiricists  developed  these  principles  into  the  tra- 
ditional "laws  of  the  association  of  ideas."  They  are  the 
laws  of  similarity,  contrast,  and  contjygyjty  in  time  or  space. 
An  idea  calls  up  another  idea  because  it  is  similar  to  it,  or 
because  it  contrasts  with  it,  or  because  it  has  been  connected 


284 


PSYCHOLOGY 


with  it  in  time  or  in  space.  Since  that  time  these  four  laws 
of  association  have  been  reduced  to  two  :  the  law  of  similarity 
and  the  law  of  continuity.  The  tendency  of  many  modern 
psychologists  is  to  make  a  still  further  reduction.  They 
assert  that  all  cases  of  associative  recall  may  be  placed  under 
the  law  of  contiguity. 

The  Laws  of  Association.  —  The  so-called  laws  of  associa- 
tion have  been  looked  upon  as  an  explanation  of  associative 
recall,  rather  than  as  a  statement  of  the  facts  of  recall.     For 
^"instance,  according  to  the  law  of  similarity,  one  thing  was 
^  supposed  to  recall  another  because  of  the  similarity  between 
them.     Now,  the^  statement  that  one  idea  recajls  another 
Because  it  is  similar  to  the  idea  recalled,  and  the  statement 
that  a  similar  idea  is  recalled  are  two  entirely 


fe 

f 

|'i 


ments.  It  might  well  be  that  similar  things  tend  to  be  re- 
called together,  and  yet  the  similarity  may  not  be  the  cause 
of  the  recall.  We  shall  return  to  this  point  later. 

It  is  also  true  that  the  laws  of  association  have  been  con- 
cerned with  the  recall  of  associated  ideas  and  not  with  the 
formation  of  associations.  It  is  evident  that  the  process  of 
forming  associations  and  the  process  of  recalling  associated 
ideas  after  the  associative  connections  have  been  formed  are 
different  processes.  And,  further,  the  reason  for  forming 
the  associations  may  not  be  the  reason  why  the  associated 
ideas  are  recalled.  To  this  point  we  shall  also  return. 

Contiguity.  —  Accepting  the  prevailing  theory  that  in  the 
law  of  association  we  may  find  the  explanation  of  associative 
recall,  we  incline  to  the  belief  that  a  single  law  —  the  law  of  con- 
tiguity —  will  cover  all  cases  of  associative  recall.  This  law 
may  be  stated  as  follows:  Objects  or  events  which  have  been 

^•••••^  •     ^"^^^^^^^^^"''•'••^'•^^^•••••••••••••••^•l 

will  be  revived  together  whenever  any 


member  of  the  group  is  present  in  consciousness     Any  mem~ 
ber  of  an  associated  group  of  experiences  tends  to  awaken 
the  other  members  of  the  group.     Here  again  psychological 
language  is  figurative  to  a  high  degree.     We  often  say,  for 
instance,  that  one  idea  has  an  attraction  for,  a  tendency  to 


ASSOCIATION  285 

suggest,  the  ideas  which  have  been  associated  with  it.  What  , 
is  really  meant  is  that  the  neural  process  involved  in  the  ( 
given  idea  tends  to  spread  to  other  centres  which  have  been  | 
excited  on  former  occasions  at  the  same  time. 

Now,  since  any  given  object,  event,  or  idea,  has  been  asso- 
ciated with  many  different  things  in  the  past,  the  general  law 
of  contiguity  is  not  specific  enough  to  explain  why  one,  rather 
than  another  of  these  past  associates  is  recalled.    We  may 
narrow  the  problem  by  saying  that  the  idea  which  is  most 
closely  associated  will  be  recalled,  or  in  neurological  terms, 
«  ^  the^jjability  of  the  given  mental  content  to  brinj  to  wn-   I 
J\f     sciousness  one  rather~than  another  of  its  past  ag^n'atpg-  is  I 
\\r        determined  by  the  permeability  of  the  brain  pathways  con-  1 
necting  the  bruin  centres.     The  neural  impulse  will  follow 
the  most  permeable  pathway.     But  to  say  that  the  most 
closely  associated  idea  will  be  recalled  is  proceeding  in  a  cir- 
cle, unless  we  can  describe  the  conditions  which  determine 
the  "closeness  of  association."    We  have  touched  upon  this 
point  in  discussing  associative  recall  in  memory.     We  found 
that  the  operation  of  the  law  of  association  is  modified  by 
several  conditions.     For  instance,  the  closeness  of  associa- 
tion may  be  determined  by  any  one,  or  by  several  of  the  fol- 
lowing conditions :  Recency,  frequency,  and  vividness  of  the  ' 
ssociated  experiences;  the  context  of  thought  in  the  mind 

the  time,  and  the  dominant  plan  or  purpose  uppermost  in 
the  mind.  While  these  conditions  determine  the  direction  of 
associative  recall,  the  general  fact  remains  that  anv  yiyen 
mental  content  always  recalls  something  that  has  been  for- 
merly experiencecijvith  it.  ;,L'h1s  Is  the  la.w  nt  rnnMgm'ty. 

Similarity. — Now,  it  may  be  objected  that  the  so-called 
association  by  similarity  is  an  exception  to  the  law  of  con- 
tiguity— that  an  idea  is  often  recalled  because  it  is  similar  to 
something  we  perceive  or  to  something  that  we  may  be  think- 
ing of  at  the  time.  And,  further,  it  may  be  said  that  it  is  a 
common  occurrence  to  have  some  presentation  or  idea  in  the 
mind  call  up  an  idea  which  has  never  been  experienced  pre- 


286  PSYCHOLOGY 

viously  with  it.  For  example,  I  may  meet  a  stranger  whom 
I  have  never  seen  before  and  immediately  I  think  of  a  friend. 
Here  apparently  is  a  case  of  recall  where  the  mental  contents 
have  never  been  experienced  together  before.  To  explain 
such  cases,  the  law  of  similarity  has  been  evoked.  And  so  it 
is  said  that  the  stranger  reminds  me  of  my  friend  because  of 
the  similarity  existing  between  them.  If,  however,  we  wish 
to  explain  psychologically  why  I  thought  of  my  friend  when 
I  saw  the  stranger,  we  could  make  no  greater  blunder  than  to 
assign  similarity  as  the  cause  of  the  recall,  for  jthe  similarity 
appear?  '"  r^ymind  oplv  af^er  the  recall  has  taken  place. 
Instead  of  the  sequence:  (i)  sight  of  the  stranger,  (2)  con- 
sciojisness  of  similarity  to  a  friend,  (3)  thought  of  my  friend, 
we  really  have  is:  (i)  sight  of  the  stranger,  (2)  thought 
my  friend,  (3)  consciousness  of  the  similarity.  It  is  evi- 
.  v^t  that  similarity  arises  only  when  the  two  terms  compared 
1  are  already  in  consciousness.  But  what  we  are  seeking  is 
some  principle  to  explain  why,  given  the  first  term,  the 
second  term  appears.  If  we  analyze  the  situation  more 
closely,  we  shall  see  that  thisjpjincipje^£_t&e^jd^ 

grm'tY  fl|ftpr..o.U  While  the  stranger  as  a  total  experience  has 
never  been  associated  with  my  friend,  some  part  of  him  has. 
It  may  be  the  shape  of  his  nose  which  is  identical  with  that 
of  my  friend's.  This  particular  shape  of  nose  js  a_part  of 
my^fn^nH's  make-up  which  IJiave  experienced  injconngction 
wi^1h_j11  hie  nthpr^rl^iT^ejjstirs  many  times.  So  when  I 

meet  this  feature  of  my  friendm*  the  stranger  it  recalls  its 
former  associates.  It  is  plain  that  what  r^irft  in  ^^  of 
so-called  association  by  similarity  is  that  some  feature  of  the 

hrpakl'nff 


from  its  immfffa'ate  asgnrigff^  grQfV|prr  frr  itrmlf  ""rtr'n  ~f  its 
former  associates  whir*1  ™rr>v>ing  ^bprpwith  tr>  fnrm  tJif  new 
object^  of  th"11^1"  "l  Judd2  uses  the  following  diagram  to 
illustrate  association  by  similarity. 

1  James:  "Principles  of  Psychology." 

2  "Psychology,"  p.  235. 


ASSOCIATION 


Now,  while  we  may  say  that  any  experience  tends  to  call 
up  similar  experiences,  we  cannot,  however,  explain  the  recall 
psychologically  by  the  principle  of  similarity.  Therefore  the 
law  of  association  by  similarity  holds  only  as  a  statement  of 
fact  and  breaks  down  as  a  psychological  explanation  of  asso- 
ciation. It  is  true  that  sim- 
ilars recall  similars,1  but  it 
is  not  the  consciousness  of 
their  similarity  that  brings 
about  the  recall. 

It  is  plain  that  when  we 
perceive  similar  things  the 
fact  that  they  are  similar 
attracts  attention.  For  this 
reason  they  become  associ- 
ated, and  afterward  the  one 
will  recall  the  other,  because 
of  the  principle  of  contigu- 
ity. .Similarity  is  therefore 


.one  of  the  prinriplp^  nr  rnn- 

ditions  for  the   formation  .of 

Associations,  but  is  not  the 


FIG.  70. — To  apply  this  figure  to  the 
case  cited:  The  circle  A  represents 
a  single  feature  (the  shape  of  the 
stranger's  nose);  b,  b,  b,  etc.,  repre- 
sent his  other  features.  In  my  past 
experiences  A  has  been  a  part  of 
another  system  (the  features  of  my 
friend).  When  A  attracts  my  atten- 
tion, it  breaks  away  from  its  present 
b,  b,  b,  etc.,  and  revives  its  old  asso- 
ciates, c,  c,  c,  etc. 


explanation  nf  Associative^1 
recall. .,  Any  relation  between  things  or  ideas  serves  to  at- 
tract the  attention  and,  consequently,  becomes  the  condition 
for  the  formation  of  associations.  The  relation  of  contrast, 
cause  and  effect,  and  the  spatial  and  temporal  relations,  to- 
gether with  similarity,  are  favorable  conditions  for  associative 

1  We  might  even  say  that  objects  and  events  are  recalled  because  they  are 
similar  to  objects  and  events  perceived  or  thought  of.  But  when  making  such 
a  statement,  we  must  understand  that  we  are  making  physical  and  not  psycho- 
logical descriptions.  I  might  say  that  it  was  because  my  friend  is  similar  to 
the  stranger  that  I  think  of  him.  This,  of  course,  is  true  in  so  far  as  I  am 
merely  pointing  out  physical  traits.  It  is  because  the  two  physical  objects  have 
the  same  character  that  the  consciousness  of  the  one  is  followed  by  the  con- 
sciousness of  the  other,  but  this  is  quite  different  from  saying  that  the  con- 
sciousness of  the  one  is  followed  by  the  consciousness  of  the  other  because  of 
the- consciousness  of  the  similarity. 


288  PSYCHOLOGY 

formation.  They  serve  to  hold  mental  states  together  in  the 
focus  of  attention  until  the  associative  connections  are  formed. 
But  the  psychological  conditions  present  during  the  formation 
of  associations  may  not  be  present  during  recall.  I  may, 
therefore,  be  attracted  to  two  objects  or  events  because  they 
are  similar,  or  because  one  contrasts  with  the  other,  or  because 
one  is  the  cause  or  the  effect  of  the  other.  But  during  the 
process  of  recall  these  relations  do  not  enter  into  conscious- 
ness. 

We  are,  therefore,  brought  back  to  the  law  of  contiguity 
as  the  law  of  association.  Even  this  law  does  not  explain 
associative  recall  psychologically.  Psychologically,  it  is  only 
a  statement  of  facts.  There  is  no  psychological  reason  why 
mental  states  that  occur  together  should  be  recalledJjQgether. 
The  real  reason  will  be  found  in  the  neural  processes  back  of 
the  mental  states. 

Partial  and  Total  Recall. — There  is  then  no  difference 
of  kind  between  the  so-called  associations  by  similarity  and 
associations  by  contiguity.  Both  make  use  of  the  same  prin- 
ciple of  recall — contiguity  of  experiences.  There  is,  how- 
ever, an  important  distinction.  In  one  the  contiguity  Is  hid- 
den  and  in  the  other  it  is  superficial  and  plainly  evident  to 

im^MlMNVMfllMMManwv   *>M*>v4IB'INMI«HMHMMRM>'V'l^VHVQHMMHVMMMM9H*VMWlikWM*W<i^*lV'*MI11*^1^^^ 

observation.  When  a  given  experience  as  a  whole  calls  up 
experiences  that  have  been  associated  with  it,  the  connection 
is  evident,  but  when  only  part  of  a  given  experience  is  active 
in  bringing  up  its  past  associates,  the  connection  is  hidden. 
In  the  latter  case,  the  given  experience  is  analyzed  or  broken 
up  into  constituent  elements,  one  of  which  has  been  connected 
with  some  former  experience  and  for  this  reason  calls  it  up. 
In  the  former  case  the  given  experience  acts  as  a  whole  and 
therefore  calls  up  only  those  experiences  which  have  been 
associated  with  it  in  its  totality.  The  so-called  "association 
by  contiguity"  is  therefore  very  much  limited  in  scope.  The 
distinction  is  the  distinction  that  we  have  already  made  be- 
tween partial  and  total  recall.  Association  by  similarity  is 
simply  a  case  of  partial  recall  and  occurs  when  the  present 


ASSOCIATION  289 

contents  of  consciousness  are  analyzed  and  evaluated  and  the 
pertinent  elements  used  as  connecting-links  for  the  next  idea. 
Not  only  are  the  threads  of  thought  multiplied  many  times 
in  this  form  of  associative  recall,  but  the  subtle  and  delicate 
identities  of  thought  are  brought  to  light.  This  type  of  recall 
characterizes  the  great  thinker.  Hamlet's  soliloquy  furnishes 
an  excellent  illustration  of  the  subtle  and  hidden  association 
of  ideas.  On  the  other  hand,  mere  surface  contiguity  calls  out 
trains  of  mechanical  associations.  This  form  of  recall — total 
recall1 — is  illustrated  on  page  250.  , — - 

Falsification  of  Association. — Where  associative  connec- 
tions are  not  firmly  fixed,  suggestions  given  by  others  may 
falsify  the  nature  of  the  associations.  Such  falsification  of 
association  is  especially  manifest  in  children  when  they  are 
being  questioned  about  actual  events  which  they  have  wit- 
nessed. If  the  questions  have  suggestions  in  them,  the  force 
of  the  suggestions  may  modify  the  actual  connections  made 
in  the  child's  mind,  so  that  he  is  unable  to  give  a  correct 
report  of  what  happened.  Persons  of  weakened  mentality  or 
even  the  normal  individual  when  fatigued  or  excited  during 
long  examinations  may,  by  skilfully  arranged  questions,  be 
led  to  give  false  testimony  in  court.  In  certain  cases,  ques- 
tions which  presuppose  a  certain  answer — leading  questions— 
or  questions  which  demand  the  answer  which  they  suggest, 
will  actually  set  up  associative  connections  in  the  mind  of  the 
witness,  causing  him  to  give  false  testimony.  We  have  al- 
ready referred  to  this  in  our  treatment  of  memory.  Those 
who  wish  a  discussion  of  this  phase  of  the  subject  may  read 
Miinsterberg's  "On  the  Witness  Stand,"  or  Whipple's  article 
"The  Observer  as  Reported:  A  Survey  of  the  Psychology  of 


1  Usually  three  degrees  of  activity  in  recall  are  distinguished:  (i)  Total 
recall,  (2)  partial  recall,  and  (3)  focal  recall.  Total  recall  embraces  those  cases 
where  the  whole  of  a  present  thought  is  active  in  recalling  the  next  thought, 
partial  recall  where  a  part  only,  and  focal  recall  where  some  single  element  or 
feature  is  active  in  recall.  Focal  recall  is,  however,  simply  an  extreme  case  of 
partial  recall. 


2 QO  PSYCHOLOGY 

Testimony."1  An  excellent  German  work  treating  of  this 
subject  is  Stern's  "Beitrage  zur  Psychologic  der  Aussage." 

Association  Tests. — Individual  differences  in  the  character 
and  rapidity  of  associations  may  be  studied  by  means  of 
very  simple  association  tests.  In  general,  the  more  nearly 
alike  the  surroundings  and  past  life  of  individuals,  the  more 
their  associations  will  be  alike.  For  instance,  if  we  should 
give  the  same  list  of  stimulus  words  to  members  of  the  same 
family,  asking  each  to  respond  with  the  first  thought  that 
comes  to  mind  when  he  hears  the  stimulus  word,  we  should 
find  a  striking  similarity  in  the  character  of  their  associations. 
This  is  to  be  expected  from  the  nature  of  associative  connec- 
tions. 

There  are  several  forms  of  association  tests.  We  may 
ask  the  subject  to  pronounce  a  large  number  of  words  just  as 
rapidly  as  he  can  think  of  them.  He  then  starts  with  any 
word  he  wishes  and  pronounces  the  words  as  fast  as  they  arise 
in  his  mind  until  stopped  by  the  experimenter,  who  has  noted 
down  the  words  and  recorded  the  time  of  the  associations. 
Such  associations  are  termed  (i)  uncontrolled  associations.  Or 
we  may  place  a  restriction  on  the  character  of  the  associa- 
tions to  be  given,  in  which  case  the  associations  are  termed 
(2)  controlled  associations.  Three  forms  of  the  controlled  as- 
sociations have  been  used  very  widely:  (a)  Part- whole,  (6) 
genus-species,  and  (c)  opposites.  In  the  part-whole  test,  a 
list  of  stimulus  words,  printed  on  a  slip  of  paper,  is  handed  to 
the  subject  who  has  been  instructed  to  name  the  whole  thing 
of  which  each  word  is  a  part.  The  total  time  required  to 
make  the  associations  is  recorded  together  with  the  responses. 
Thus,  if  a  stimulus  word  is  "door,"  the  subject  must  respond 
with  the  name  of  something  of  which  "door"  is  a  part,  as 
"house"  or  "barn"  or  "building." 

In  the  genus-species  test,  the  procedure  is  the  same,  ex- 
cept that  the  subject  is  required  to  respond  to  each  stimulus 
word  by  the  name  of  something  which  belongs  in  the  class 

1  Psychological  Bulletin,  vol.  VI,  pp.  153-170,  May,  1909, 


ASSOCIATION  291 

indicated  by  it.  For  example,  if  the  word  "tree"  is  given, 
the  response  must  be  some  kind  of  tree,  "maple- tree,"  or 
"apple-tree"  or  "oak-tree,"  etc. 

The  opposite-test  requires  that  a  word  which  means  just 
the  opposite  of  the  stimulus  word  be  given.  To  the  word 
"bad"  the  subject  must  respond  by  the  word  "good,"  to 
"sane"— "insane,"  to  " high "—" low,"  and  so  on.  The 
number  of  stimulus  words  may  be  varied  at  will,  but  in  each 
case  the  time  and  the  character  of  the  responses  must  be  re- 
corded. In  the  part-whole,  genus-species  and  opposites,  the 
associative  responses  are  controlled  or  restricted  by  the  set 
of  the  mind  given  by  the  instructions  just  before  the  test. 
In  the  uncontrolled  associations  there  is  no  such  restriction. 

The  associations  are  still  uncontrolled  when  the  subject 
is  given  a  list  of  stimulus  words  and  he  responds  with  any 
word  that  comes  to  his  mind.  The  experimental  study  of 
associative  connections  may  be  carried  on  for  a  number  of 
purposes:  To  investigate  the  individual  differences  in  the 
thought  content  and  thought  processes  as  conditioned  by 
sex,  age,  training;  to  determine  the  effect  of  fatigue,  drugs, 
etc.,  on  the  associative  recall;  to  diagnose  abnormal  mental 
disturbances  and  to  detect  hidden  mental  tendencies  and 
wishes  or  intentionally  withheld  information.1 

Since  the  formation  of  associations  depends  upon  original 
experiences,  it  follows  that  the  character  of  associative  con- 
nections is  a  clew  to  the  nature  of  the  original  experience.  If 
ideas  call  up  the  ideas  which  have  been  connected  with  them, 
one's  past  must  necessarily  be  revealed  by  the  character  of 
his  ideas.  If  we  should  ask  a  number  of  persons  to  give  the 
first  idea  that  comes  into  mind  when  a  stimulus  word  is  pro- 
nounced, their  different  associations  would,  in  most  cases, 
reflect  some  feature  of  their  past.  For  instance,  in  a  list  of 
stimulus  words  given  to  a  class  in  psychology  was  the  word 
"Becky."  Eight  members  of  the  class  responded  to  the 

1  For  a  description  of  association  tests,  see  Whipple's  "  Manual  of  Mental 
and  Physical  Tests,"  zd  ed.,  pp.  409-455. 


PSYCHOLOGY 

word  by  "Grand,"  three  by  "Frances  Starr,"  and  the  rest 
by  scattered  associations.  It  turned  out  that  twelve  mem- 
bers of  the  class  had  the  week  before  witnessed  at  the  Grand 
Opera  House  a  play  entitled  "The  Case  of  Becky,"  in  which 
Frances  Starr  played  the  title  role.  Of  the  twelve,  all  but 
one  indicated  by  their  associations  the  fact  that  they  had 
seen  this  play. 

James  quotes  an  anecdote  from  Professor  H.  Stein  thai1 
which  illustrates  the  fact  that  the  character  of  our  associa- 
tions are  clews  to  our  past.  The  substance  of  the  anecdote 
is  as  follows:  Six  strangers  found  themselves  in  the  compart- 
ment of  a  railway-carriage.  One  of  the  party  undertook  to 
name  the  occupation  of  each  member  of  the  party  upon  the 
condition  that  each  answer  a  simple  question.  They  all 
agreed,  whereupon  he  wrote  a  question  upon  five  slips  of 
paper  and  gave  one  to  each  of  his  companions  with  the  re- 
quest to  write  the  answer  below.  When  the  leaves  were 
returned,  he  read  the  answers  and  without  hesitation  said  to 
the  first,  "You  are  a  man  of  science";  to  the  second,  "You 
are  a  soldier";  to  the  third,  "You  are  a  philologer";  to  the 
fourth,  "You  are  a  journalist";  to  the  fifth,  "You  are  a 
farmer."  All  admitted  that  he  was  right.  When  the  stranger 
left  the  railway-carriage  they  compared  notes  and  discovered 
that  he  had  written  the  same  question  upon  each  slip  of 
paper.  It  was:  "What  being  destroys  what  it  has  itself 
brought  forth?"  The  naturalist  had  answered,  "Vital 
force";  the  soldier,  "War";  the  philologist,  "Kronos";  the 
journalist,  "Revolution";  and  the  farmer,  "A  boar." 

We  may  not  only  study  the  character  of  association,  but 
we  may  measure  the  time  required  to  recall  an  association 
word.  When  a  stimulus  word  is  pronounced,  it  requires  a 
certain  length  of  time  before  the  subject  can  think  of  an 
association  word.  If  the  word  "day"  is  given,  the  subject 
may  respond  with  the  word  "night."  If  we  measure  the 
time  between  the  giving  of  the  stimulus  word  and  the  re- 
1  "Einleitung  in  die  Psychologic  u.  Sprachwissenschaft,"  p.  166. 


ASSOCIATION  293 

sponse,  we  shall  find  that  the  association  time  varies  for 
normal  associations  from  one  to  two  seconds.  But  under 
certain  conditions  there  is  a  marked  lengthening  of  the  time. 
If  the  stimulus  word  arouses  an  emotional  complex,  or  if  the' 

^-r '  • —i    ••  -  .. ,—  *_  '  — 

subject  does  not  gjye  the  first  association  for  fear"  of  "giving 
himself _awa_yz^  and  hunts  for  another  association,  the  asj?o- 
ciation_tim€Ljs  lengthen^  Therefore,  both  the  character 
ofan  association  and  the  time  required  to  form  the  associa- 
tion are  significant  in  detecting  past  experiences.  To  illus- 
trate: The  following  test  was  made  upon  four  students  in 
psychology  for  the  purpose  of  detecting  which  one  of  the 
four  had  read  a  certain  article  in  the  morning  paper,  which 
only  one  had  seen.  The  procedure  was  as  follows:  The  four 
students  were  left  alone  in  a  room.  One  of  them  read  the 
following  article,  but  which  one  the  instructor  did  not  know. 

SPOT   ON   MONUMENT 
CAUSES  WASHINGTON  PEOPLE  TO  BELIEVE  "HUMAN  FLY"  is  BUSY 

WASHINGTON,  May  7. — Rumors  that  a  New  York  "human  fly" 
who  has  been  scaling  the  office  buildings  here  was  climbing  the  side 
of  the  555-foot  Washington  Monument  gave  the  city  no  end  of  ex- 
citement to-day.  Some  one  suddenly  discovered  a  black  spot  on  the 
side  of  the  shaft  about  150  feet  from  the  top,  and  then  the  report 
started. 

Hundreds  of  people  rushed  to  the  monument  grounds.  Along 
Pennsylvania  Avenue  crowds  collected  at  every  corner,  and  windows 
and  doorways  rapidly  filled  with  people.  Investigators  said  that  the 
supposed  spot  was  only  a  spot  left  by  the  rain. 

The  War  Department,  which  controls  the  monument,  was  be- 
sieged with  telephone  calls.  Nearly  three  hours  after  the  first  ex- 
planations a  telephone  message  from  the  Capitol  said  the  legislators 
were  watching  the  spot  through  opera-glasses  and  were  convinced 
that  it  moved  occasionally. 

A  list  of  fifteen  stimulus  words  (the  words  in  column  (i) 
of  Table  I),  in  which  six  "dangerous"  words  were  placed— 
opera,  spot,  human,  climb,  fly,  Washington — was  prepared. 
The  four  students  were  then  given  this  list  separately.  Their 


294 


PSYCHOLOGY 


responses  and  association  time  were  taken  and  are  given  in 
the  table.  The  subjects  are  designated  by  the  letters  B,  M, 
W,  and  C.  B  gave  the  responses  in  column  (2),  M  in  column 
(3)*  ^  m  column  (4)  and  C  in  column  (5). 


TABLE  I 


STIMULUS  WORDS 

RESPON 

SES 

(I) 

(2)B 

(3)M 

(4)W 

(S)C 

i.  Summer 

winter  i 

winter  i 

winter  i 

winter  i 

2.  Opera* 

play  i 

singing  i 

house  2 

music  i 

3-  Day 

night  i 

night  i 

night  i 

night  i 

4.  Spot* 

blotch  i 

black  2 

board  i 

piece  i 

5.  Table 

desk  i 

chair  i 

legs  i 

cover  i 

6.  Human* 

man  [5] 

life  4 

men  i 

divine  4 

7.  Come 

go  i 

go  i 

go  2 

go  2 

8.  Climb* 

mountain  [3] 

crawl  i 

tree  i 

tree  2 

9.  Window 

door  i 

shutter  2 

glass  i 

cushion  i 

10.  See 

land  3 

bay  2 

water  i 

ocean  2 

ii.  Tie 

collar  2 

red  2 

road  i 

knot  2 

12.  Fly* 

wasp  [4) 

bird  i 

wings  i 

bugs  i 

13.  Book 

ledger  2 

paper  2 

leaves  i 

14.  Washington* 

Jefferson  [3] 

Lincoln  i 

capital  i 

D.C.  I 

15.  Sour 

sweet  i 

sweet  2 

bitter  i 

sweet  i 

The  dangerous  words  are  marked  in  the  table  with  an 
asterisk.  The  numerals  in  columns  (2),  (3),  (4),  and  (5) 
represent  in  seconds  the  association  times  for  each  response. 
The  time  was  taken  with  an  ordinary  stop-watch,  since  the 
test  was  made  only  for  rough  demonstration  purposes.  For 
more  exact  laboratory  work,  the  time  may  be  taken  in  hun- 
dredths  of  seconds. 

Subject  B  was  correctly  designated  as  the  guilty  person 
by  the  results  of  the  tests.  He  passed  two  of  the  dangerous 
words  without  lengthening  the  time  of  reaction.  But  when 
he  came  to  "human,"  his  first  association  was  "fly,"  but 
since  that  would  have  indicated  his  acquaintance  with  the 
article  just  read,  he  did  not  give  it.  It  required  several 
seconds  to  change  the  association  word  to  "man."  Therefore 
his  association  became  "blocked."  Sometimes  it  occurs  (not 


ASSOCIATION  295 

shown  in  this  test)  that  the  blocking  of  an  association  will 
be  delayed  and  appear  in  the  associations  immediately  fol- 
lowing a  dangerous  word  which  the  subject  passes  success-  / 
fully.     This  takes  place  where  there  is  more  at  stake  than  in  / 
the  demonstration  test  just  given.     What  happens  in  such  ) 
cases  is  that  an  emotional  disturbance  started  by  the  danger- 
ous word  requires  time  to  develop,  and  therefore  shows  its  ' 
effect  in  later  associations. 

Attempts  have  been  made  to  apply  association  tests  to 
suspected  criminals  for  the  purpose  of  detecting  their  fa- 
miliarity with  places  and  events  connected  with  crimes.1 
The  association  method  has  also  been  used  in  the  diagnosis 
of  cases  of  hysteria  and  neurasthenia.  It  is  supposed  that  I 
such  mental  affections  are  due  to  certain  past  experiences  of  \ 
highly  emotional  character  which  have  been  repressed  and  I 
submerged  in  consciousness.  The  patient  either  desires  not 
to  give  expression  to,  or  has  half-forgotten  these  experiences. 
In  either  case,  they  are  nevertheless  constant  sources  of  men- 
tal disturbances.  By  giving  long  lists  of  words  properly 
selected,  the  physician  is  able  to  detect  those  which  show 
abnormal  associations,  and  so  indicate  that  they  have 
"tapped"  the  emotional  complexes  in  the  patient's  mind. 
In  this  way  it  is  often  possible  to  discover  the  nature  of  the 
mental  disturbances — to  uncover  the  experiences  which  have 
been  disturbing  the  mental  equilibrium  of  the  patient.  Past 
experiences  which  lie  at  the  bottom  of  hidden  and  unex- 
pressed desires,  secret  worries,  and  divergent  or  antagonistic 
tendencies  which  are  the  beginning  of  mental  dissociation  are 
brought  to  the  surface  of  consciousness  by  arousing  sup- 
pressed associations.  Such  associations  may  reach  back  to 
the  early  life  of  the  patient,  even  to  the  years  preceding 
adolescence.  It  is  here  that  Freud  has  rendered  important 
service  to  abnormal  psychology  through  the  method  of  psy- 

1See  Miinsterberg's  "On  the  Witness  Stand";  also  lectures  given  by  Jung 
at  Clark  University,  on  "The  Association  Method,"  American  Journal  of  Psy- 
chology, XXI,  1910,  pp.  219-270. 


296  PSYCHOLOGY 

.cho-analysis.  This  method  supplements  the  association 
i  method  by  seeking  through  a  series  of  questions  to  draw  out 
the  patient  and  induce  him  to  give  full  expression  to  the  sup- 
pressed or  half-forgotten  experiences,  which  nevertheless  pre- 
serve subconscious  associative  connections  with  the  present 
consciousTife! When  these  associative  connections  are  re- 
awakened, the  unity  and  equilibrium  of  consciousness  is 
restored. 

An  interesting  phase  of  Freud's  theory  is  the  importance 
he  attaches  to  dreams  as  clews  to  hidden  experiences,  sup- 
pressed desires,  and  wishes.  He  believes  that  in  many  cases 
dreams  are  symbols  of  the  wishes  which  we  do  not  allow 
ourselves  to  express  in  waking  moments.  A  careful  analysis 
of  our  dreams  will  often  enable  us  to  determine  what  these 
suppressed  wishes  are. 

The  work  of  Jung  and  Freud  has  done  much  to  demon- 
strate the  fact  that  associative  connections  once  formed  are 
not  entirely  lost,  even  though  we  may  not  under  normal 
conditions  be  able  to  recall  them.  The  threads  of  past  asso- 
ciative bonds  may  remain  and  exert  a  much  more  powerful 
influence  on  our  mental  life  than  we  ordinarily  suppose.  Ex- 
periences which  we  have  forgotten  may  play  a  part  in  deter- 
mining the  course  of  our  thought  and  action.  No  matter 
how  much  the  individual  may  wish  to  shake  loose  the  bonds 
which  connect  him  with  his  past  experiences,  or  how  success- 
ful he  has  been  in  putting  them  out  of  his  thoughts,  their 
impress  has  been  left  upon  him,  and  is,  therefore,  a  compo- 
nent element  in  the  underlying  strata  of  his  character. 

Physiological  Basis  of  Association. — We  may  easily  form 
some  conception  of  the  neural  mechanism  involved  in  the 
associations  which  are  set  up  between  presentations  and  the 
motor  responses  which  we  make  to  them.  In  such  cases,  the 
nervous  impulses  aroused  in  the  sensory  centre  discharge  into 
motor  centres  and  pathways.  We  have  already  seen  that 
this  discharge  of  sensory  centres  into  motor  pathways  is  a 
general  characteristic  of  the  central  nervous  system.  In  a 


ASSOCIATION 

large  number  of  cases,  the  particular  motor  response  thati 
becomes  associated  with  a  given  presentation  is  one  that  has  V 
been  gradually  selected  and  stamped  in  because  of  its  fitness  / 
in  adjusting  the  individual  to  the  presented  situation.     TheJ 
particular  motor  response  is,  therefore,  the  successful  one  of 
the  many  responses  that  were,  from  the  beginning,  natively 
associated  with  the  given  presentation.     Such  is  the  method 
of  learning  motor  responses  by  trial  and  error. 

But  when  we  ask  how  one  presentation  comes  to  be  asso- 
ciated with  another  presentation,  as  is  the  case  in  association 
by  contiguity,  the  problem  set  for  physiological  psychology  is 
much  more  difficult  than  is  the  case  where  one  term  of  the 
association  is  a  motor  reaction.  When,  for  instance,  the 
child  sees  a  horse  for  the  first  time  and  hears  the  word  pro- 
nounced, how  does  the  visual  centre,  corresponding  to  the 
sight  of  the  horse,  come  to  be  connected  with  the  auditory 
centre,  corresponding  to  the  sound  of  the  word,  so  that  after- 
ward the  one  arouses  the  other?  In  the  first  instance,  each 
centre  is  aroused  independently  of  the  other.  Is  the  mere 
fact  that  they  are  active  at  the  same  time  sufficient  explana- 
tion for  the  fact  that  a  neural  pathway  is  opened  between 
the  centres,  so  that  when  afterward  the  child  sees  a  horse, 
the  word  comes  to  the  mind,  or  when  he  hears  the  word  the 
visual  image  of  the  horse  comes  to  mind  ?  At  present,  physi- 
ology cannot  answer  the  question,  so  we  shall  have  to  accept 
the  most  reasonable  theory.  McDougall1  proposes  the  drain- 
age theory  to  account  for  the  formation  of  neural  connections. 
According  to  this  theory,  when  the  child  sees  the  horse,  his 
visual  centre  is  excited,  then  he  hears  the  word  " horse"  and 
his  auditory  centre  is  excited.  The  attention  shifts  from  the 
visual  appearance  of  the  horse  to  the  sound  of  the  word. 
Accordingly,  the  activity  aroused  in  the  visual  centre  is 
drained  off  by  the  auditory  centre.  Thus  a  neural  pathway 
between  the  two  centres  is  formed. 

1  "Physiological  Psychology,"  p.  126. 


I 


298  PSYCHOLOGY 

Ladd  and  Woodworth1  are  of  the  opinion  that  the  drain- 
age theory  does  not  explain  all  cases  of  association  by  con- 
tiguity and,  further,  that  in  some  cases  where  complete  drain- 
age between  centres  could  very  well  take  place,  no  associative 
connections  are  formed.  Such  cases  are  found,  for  instance, 
in  the  shifting  of  the  attention  in  the  staircase  or  bent  card- 
board figures.  Here  attention  shifts  from  one  aspect  of  the 
figure  to  the  other,  affording  a  splendid  opportunity  for  the 
drainage  of  one  centre  by  the  other.  Yet  there  is,  so  say 
these  authors,  no  evidence  of  the  association  between  the 
two  perceptions  of  such  figures.  They  agree  that  in  the  for- 
mation of  associative  connections  nerve  currents  must  pass 
between  the  different  centres  involved.  But  it  is  not  the 
mere  drainage  of  one  centre  by  the  other  that  sets  up  the 
associative  connections.  It  is  not  the  shifting  of  attention, 
<but  the  movement  of  attention  with  anticipation  or  expec- 
Itancy  of  something  to  come,  with  a  lingering  of  what  has 
|just  gone.  In  neural  terms,  this  expectancy  corresponds  to 
a  damming  up  of  energy  in  the  first  centre  until  the  expected 
stimulus  comes;  then  it  discharges  into  the  centre  aroused 
by  the  stimulus.  Illustrating  the  formation  of  association 
between  the  visual  appearance  of  a  new  acquaintance  and 
his  name,  these  authorities  say:  "If  one  says,  for  example, 
'Let  me  present  Mr.  A,'  the  nervous  energy  aroused  by  the' 
sight  of  the  man  is  perhaps  held  in  check  till  the  name  is 
spoken,  and  then  discharged  into  the  centre  aroused  by  the 
auditory  stimulus  which,  on  account  of  its  being  aroused  by 
this  stimulus,  would  the  more  readily  attract  other  nerve- 
currents  having  a  partially  open  path  into  it.  Such  a  condi- 
tion would  account,  also,  for  the  special  clearness  with  which 
an  expected  stimulus  is  perceived." 

1  "Elements  of  Physiological  Psychology,"  pp.  617-625. 


CHAPTER  XIII 
CONCEPTION 

Thinking. — In  perception  and  imagination  we  have  treated 
only  that  aspect  of  consciousness  which  is  concerned  with 
separate  and  particular  things  and  events.  But  conscious- 
ness includes  more  than  the  perception  or  the  imagination 
of  discrete  things.  We  are  never  aware  of  an  object  with- 
out involving  more  than  the  object  itself.  An  object  is 
always  presented  in  some  context — in  some  relation  to  other 
things.  The  pen  that  I  now  see  is  not  just  a  pen.  It  is  a 
pen  writing — my  pen — the  pen  that  7  bought  yesterday — a 
pen  made  of  steel — etc.  I  am  more  or  less  conscious  of  these 
relations  when  I  image  or  perceive  the  pen.  I  not  only  see 
the  book,  but  I  am  conscious  of  it  on  the  table  before  me — as 
belonging  to  my  friend — as  written  by  Holmes.  The  omscious- 
i\ess  of  these  relations  is  just  as  much  a  mental  content^as 
tfye_  consciousness  of  the  presented  object.  It  "Kg  the  con- 
sciousness of  rejationshipjvvhich  binds  the  discrete  elements 
of  our  mental  life  tngf^hpj.  Sometimes  our  attention  is 
fixed  chiefly  upon  the  sensory  appearance  of  the  object  and 
sometimes  upon  the  relations.  When  we  attend  primarily 
to  the  relations  between  things,  we  employ  a  phase  of  con- 
sciousness which  we  have  not  yet  discussed.  This  form  of 
conscious  activity  is  thinking. 

e  manipulation  of  data  ftfrff  in  «mnM.rinp. 


iperception,  and  imagination  in  such  a  waythatthe  relatiojg^ 
ships  existing  between  things  are  actively  attended, to. 

The1  consciousness  of  relationship  is  implicitly  present  in 
all  forms  of  consciousness,  save  perhaps  in  the  so-called  pure 
sensations.  Perception,  for  instance,  cannot  take  place  with- 
out recognition  of  the  object  perceived  and  recognition  is 

299 


300         '«*^  PSYCHOLOGY 

the  implicit  consciousness  of  the  relation  of  sameness  or 
identity.  There  is  also  present  in  the  perception  of  an  ob- 
ject, the  relations  which  the  object  bears  to  other  things. 
Sometimes  the  emphasis  is  placed  upon  the  sensory  presen- 
tation of  the  object,  while  relationships  occupy  the  back- 
ground of  consciousness.  In  thinking,  on  the  other  hand, 
the  consciousness  of  relationship  comes  to  the  front  and  is 
made  the  bridge  over  which  we  pass  from  one  discrete  ele- 
ment of  thought  to  another. 

Can  we  be  conscious  of  things  without  their  relations? 
Theoretically,  the  "pure  sensations"  (the  hypothetical  first 
sensations),  if  they  exist,  involve  no  consciousness  of  relation- 
ship. One  might  suppose  that  the  baby's  first  consciousness 
is  a  mass  of  vague,  unrecognized  experiences — that  his  first 
sensations  of  cold  and  warmth,  of  pressure  and  taste,  are 
bare  disconnected  mental  flashes  of  sensory  contents  not 
related  in  any  way  in  its  consciousness.  But,  even  here,  our 
earliest  observation  of  the  child  shows  that  he  does  relate 
his  experiences.  When  he  sees  his  mother,  nurse,  or  bottle, 
there  are  unmistakable  signs  that  he  experiences,  although 
perhaps  dimly,  a  feeling  of  familiarity  which  may  be  charac- 
terized by  "this- is -like -something- 1 -have -experienced -be- 
fore." Whether  we  look  upon  this  primitive  and  simple 
relational  experience  as  a  rudimentary  form  of  thinking  or 
not,  it  cannot  be  doubted  that  the  thinking  process  is  founded 
in  this  faint  awareness  of  sameness  or  identity.  James  says: 
"A  polyp  would  be  a  conceptual  thinker  if  a  feeling  of 
'Hollo I  thingumbob  again!'  ever  flitted  through  its  mind." 

Thought  then  adds  to  the  bare  perception  of  individual 
things  the  consciousness  of  relations  existing  between  them,  , 
thus  organizing  and  unifying  and  rendering  intelligible  what 
would  otherwise  remain  isolated  and  chaotic  in  conscious- 
ness. There  are  three  aspects  of  the  thinking  process — con- 
ception, judgment,  and  Inference.  These  aspects  are  inti- 
mately related  and  interwoven  and  really  belong  together. 
We  shall,  however,  treat  them  in  separate  chapters. 


CONCEPTION  301 

The  Concept. — As  we  said,  in  perception,  imagination,  and 
memory,  consciousness  is  concerned  with  individual  and 
particular  things.  We  perceive,  or  image,  or  remember  this 
particular  object,  or  that  particular  event.  In  short,  in 
perception  and  imagination  we  are  always  dealing  with  a 
world  of  particular  and  concrete  experiences.  We  have,  for 
instance,  known  a  number  of  individual  horses  and  we  can 
form  an  image  of  any  one  of  them,  more  or  less  perfectly. 
If  we  were  obliged,  however,  to  image  all  these  individual 
horses  when  we  wish  to  think  or  speak  of  them,  we  could 
make  very  little  progress  in  thinking  or  in  communicating 
our  ideas  to  others.  Such  a  method  would  be  a  very  cum- 
bersome way  of  making  use  of  past  experiences.  If  we  were 
content,  when  thinking  or  speaking  of  horses,  with  the  image 
of  a  single  horse,  the  thought  would  be  a  poverty-stricken 
and  fragmentary  representation  of  what  we  really  know  of 
horses,  and  anything  we  could  say  about  them  would  be 
very  much  limited  in  scope. 

What  we  need  for  the  purposes  of  thought  and  the  com- 
munication of  knowledge  is  some  form  of  consciousness  which 
will  consolidate  the  essential  elements  of  our  past  experiences 
with  similar  objects  into  a  single  mental  content  which  com- 
prehends all  of  them  at  once.  Happily,  this  need  is  supplied 
in  the  concept.  The  concept  is  the  mental  state  which  com- 
prehends  a  number  of  parti'mlam  p^p^ping  a  ^mm^n  "tr-/ 
rnent  or  group  of  qualities  in  a.  sipgl^  mpnfal  rrmtpnf  For 
instance,  the  concept  horse  refers  to  all  horses  and  attaches 
a  common  group  of  qualities  to  each  member  of  the  class. 
The  concept  John  Jones  refers  to  all  the  different  particular 
aspects  of  an  individual.  The  concept  is  therefore  'general 
and  not  particular  in  its  reference.  It  refers  to  all  the  mem- 
bers  of  a  class,  or  to  all  the  different  aspects  of  a  single  object 
and  emphasizes  a  common  or  universal  quality  which  is 
taken  to  be  the  same  throughout  a  variety  of  instances. 

The  conscious  states  which  comprise  our  thoughts  of 
horse,  wood,  dog,  tree,  London,  John  Jones,  truth,  honesty, 


302 


PSYCHOLOGY 


etc.,  are  concepts.  We  mean  by  horse  any  horse  whatso- 
ever, or  the  common  qualities  of  all  horses;  by  London,  all 
its  different  parts  and  aspects;  by  honesty,  the  essential 
character  of  all  honest  acts;  and  not  this  horse,  or  this  aspect 
of  London,  or  this  concrete  act  of  honesty. 

The  Formation  of  the  Concept. — The  formation  of  the 
concept  involves,  either  explicitly  or  implicitly,  the  process, 
of  abstraction  and  generalization.  After  the  reflective  proc- 
esses have  developed,  we  may  reform  our  old  concepts  or 
form  new  ones  according  to  logical  laws.  We  may  then, 
with  thcpavowed  purpose  of  forming  a  correct  general  no- 
tion, observe  each  individual  case  of  a  class  of  objects,  ana- 
lyze  each  into  its  elementary  qualities,  compare  the  different 
ses,  abstract  the  common  qualities,  and  then  generalize 
tiiem  into  a  concept.  This  is  the  logical  formula  for  getting 
the  universal  character  of  things.  But  nearly  all  our 
concepts  grow  up  unreflectively  out  of  our  every-day  experi- 
ence with  things  and  do  not,  therefore,  follow  this  formula. 
Concepts  begin  in  the  hazy  ideas  of  childhood  and  only 
slowly  assume  their  present  character.  In  the  unreflective 
formation  of  concepts  the  abstraction  and  generalization  of 
common  qualities  of  a  class  of  like  objects  is  not  the  result 
of  an  explicit  reflective  process,  but  is  implicitly  impressed 
upon  us  chiefly  because  the  individual  objects  of  any  given 
class  call  out  the  same  reactions.  TJie_wa^_jve__r£a£t_j£> 
individual  jilrjpr^s  is  the  most  potent  factor  in  our  Dearly 
dassificatioiLJind  definition  ojrtK?ng§^  Because  we  react  in 
the  same  way  to  different  individuals  of  the  same  class,  we 
come  to  think  of  them  in  the  same  way — to  discover  and 
emphasize  the  same  qualities  in  them.  For  instance,  we 
react  in  the  same  way  to  all  individual  chairs,  tables,  horses, 
etc.,  and  so  come  to  think  of  each  class  in  the  same  terms. 
At  first  children  define  entirely  in  terms  of  use,  or  we  may 
say  in  terms  of  their  characteristic  reactions  to  the  things 
defined.  Thus,  chair  is  "something  to  sit  on,"  table  is 
" something  to  eat  on,"  horse  is  "something  to  ride  or  drive." 


CONCEPTION  303 

Their  first  notions  are,  therefore,  determined  by  their  reac- 
tions. 

The  Psychological  and  the  Scientific  Concepts. — The  con- 
cepts which  have  grown  up  gradually  in  our  perceptual  and^ 
unreflective  experience  are  called  psychological  concepts,  to  '•' ' 
distinguish  them  from  the  concepts  whlch~are  the  result  of 
reflective  thought,  in  which  the  processes  of  comparison, 
abstraction,  and  generalization  are  purposely  instituted  in 
order  to  determine  the  exact  nature  of  things.  Concepts 
formed  in  this  way  are  called  logical  or  scientific  concepts. 
They  are  termed  "logical"  because  they  are  the  product  of 
a  more  or  less  formal  logical  procedure,  and  "scientific"  be- 
cause they  are  attempts  at  exact  formulation  and  definition 
of  meanings. 

Very  few  people  can  satisfactorily  define  water,  air,  table, 
truth,  because  they  have  never  subjected  their  experiences 
with  them  to  reflective  observation  and  analysis.  They  are 
unable  to  point  out  the  universal  and  distinguishing  qualities 
of  these  common  things.  Yet  we  all  have  a  good  working 
notion  of  them,  which  has  been  gained  in  every-day  experi- 
ence, and  which  serves  our  practical  purposes.  Thf  1"gi^-l  /,  ^ 
concepts  are,  however,  superior  instruments  of  thought  and  ^ 
action.  The  man  who  has  carefully  and  logically  thought 
out  the  nature  of  things  and  has  explicitly  formulated  their 
meanings  so  that  he  knows  exactly  what  they  include  is 
better  able  to  control  them.  Any  farmer  has  a  practical 
notion  of  trees.  His  concepts  of  elm,  oak,  hickory,  ash  have 
been  gained  through  an  extended  practical  experience,  yet 
he  is  not  able  to  take  a  position  in  the  government  horticul- 
tural service.  His  concepts  of  apple,  peach,  and  plum  are 
as  complete  as  ordinary  perceptual  experiences  can  make 
them,  yet  he  cannot  compete  with  the  student  from  the  hor- 
ticultural department  of  the  College  of  Agriculture  in  han- 
dling an  orchard. 

The  psychological   concept,   however,   is   the  basis — the    yr> 
first  stage  in  the  development  of  the  logical  concept.     Unre- 


304  PSYCHOLOGY 

flective  generalization  gives  us  our  first  notions  of  things. 
Reflective  thought  refines  and  defines  them  into  logical  con- 
cepts. 

The  General  and  the  Individual  Concept. — If  we  consider 
the  intrinsic  nature  of  the  concept  instead  of  the  manner  of 
its  formation,  we  find  two  forms:  the  general  and  the  indi- 
vidual concept.  The  general  concept  is  that  mental  state 
which  refers  to  all  the  members  of  a  class  of  objects  having 
a  common  quality  or  group  of  qualities.  Thus,  "man"  is  a 
general  concept.  We  mean  by  man  every  member  of  the 
class  and  to  each  member  we  attribute  a  universal  group  of 
qualities. 

The  individual  concept  is  that  mental  state  which  refers 
to  all  the  different  aspects  of  a  single  object.  Thus,  the 
mental  state  which  corresponds  to  "John  Jones,"  is  an  indi- 
vidual concept.  John  Jones,  as  an  actual,  concrete  exis- 
tence, has  many  different  states,  qualities,  and  activities.  I 
have,  for  instance,  met  him  in  society,  in  business,  on  the 
golf-links,  in  the  club,  etc.  No  single  image  of  John  Jones 
can  represent  him  in  all  his  totality.  The  concept,  "John 
Jones,"  on  the  other  hand,  consolidates  all  his  states,  quali- 
ties, and  activities,  as  I  have  known  them,  into  a  single  men- 
tal content.  When  I  think  John  Jones,  I  do  not  mean  John 
Jones  in  particular,  but  John  Jones  in  all  his  aspects.  Just 
as  in  the  general  concept  "man,"  I  mean  all  the  different 
individuals  of  a  class,  so  in  the  individual  concept  John 
Jones,  I  mean  all  the  different  aspects  of  his  existence.  By 
the  general  .CQn.cept-w,e-think  the  same  qualify  in  ^  rjjj™j^r 
ofjiiffexentJiHUyj^^  concept,  weJJilnk 

the.. same  individual  in  a  number  of  different  qualities. 

The  individual  concept  involves  abstraction  and  gener- 
alization quite  as  truly  as  the  general  concept.  In  forming 
the  concept  John  Jones,  we  isolate  the  qualities  which  be- 
long to  John  Jones  and  mark  them  off  as  distinct  from  those 
of  other  men.  We  generalize  when  we  think  John  Jones  in 
all  these  different  aspects. 


The  Analysis  of  the  Concept. — So  far  we/nVvespoke: 
of  that  which  the  concept  does,  its  functional  aspect.  We 
have  said  that  it  refers  to  all  the  members  of  a  class,  or  to 
all  the  characteristics  of  an  individual.  We  must  now  in- 
quire into  the  nature  of  the  concept  itself,  its  structural 
aspect.  Of  what  kind  of  "consifous  stuff "  is  the  concept 
made?  The  answer  to  this  question  will  show  us  how  a 
single  mental  state  "refers  to,"  "comprehends,"  or  "con- 
solidates" a  number  of  particular  objects  and  particular 
qualities  into  a  mental  unity. 

If  we  examine  carefully  the  content  of  any  concept,  we 
shall  find  two  constituent  elements  in  it:  (i)  The  image  and 
(2)  the  consciousness  of  meaning.  For  instance,  at  the  mo- 
ment I  think  "horse,"  the  content  of  my  consciousness  is 
made  up  of  an  image  of  some  kind  and  a  definite  G&te^of 


horse  meanings." 

The  Image. — The  image  may  be  either  concrete  or  verbal. 
In  the  case  cited,  the  image  may  be  either  the  concrete  visual 
image  of  some  particular  horse,  or  the  visual,  motor,  or 
auditory  image  of  the  word  "horse."  Any  one  of  these 
images  may  serve  as  a  means  of  attachment  for  the  meaning 
imph'ed  in  the  concept.  When  I  think  of  horses  in  general, 
I  sometimes  find  myself  entertaining  a  rather  indefinite, 
hazy,  visual  image  of  a  horse.  Sometimes  the  sound  of  the 
word  "horse,"  together  with  the  feelings  of  enunciation,  as 
though  I  were  about  to  pronounce  the  word,  "horse,"  arise 
in  my  mind.  Now,  in  the  first  case,  the  image  is  a  copy 

ige.  In  the  second  case,  the  word  image  is  purely  sym- 
__Jc.  It  serves  as  a  symbol  of  the  things  I  am  thinking 
about.  It  is  safe  to  say  that  the  wordjrjiage  is  most  com- 
monly used  in  the  concept. 

In  cases  where  the  visual  image  of  some  particular  horse 
arises  in  my  mind,  I  do  not  intend  or  mean  the  particular 
horse  imaged,  but  the  whole  class  of  horses.  It  is  perfectly 
possible  for  concrete  images  to  function  in  this  way.  In  fact, 
all  imagery  must,  in  order  to  function  in  a  concept,  be  sym- 


306  PSYCHOLOGY* 

bolic,  i.  e.,  stand  for  or  signify  something  beyond  itself.  No 
image  can  copy  all  the  varying  sizes,  forms,  and  colors  of  all 
the  individual  horses  I  have  known.  Nor  is  it  necessary 
for  the  image  to  be  like  the  things  it  stands  for,  any  more 
than  the  sign  of  a  grocery  store  needs  to  be  like  the  store 
(itself.  An  image  may  stand  for  something  beyond  itself, 
even  though  IFIs  not  Hke  it. 

e  mistaken  assumption  that  images  must  resemble  the 
things  they  signify  has  led  some  writers  to  deny  the  possibility 
of  general  ideas.  They  assert  that  only  ideas  of  individual 
and  particular  things  are  possible,  for  it  is  impossible  to 
form  a  general  image.  Locke  contended  that  a  general  idea 
of  a  triangle  is  impossible,  because  no  single  image  could  pic- 
ture all  forms  of  triangles.  But  he  neglected  the  fact  that 
the  image  of  any  particular  triangle  may  mean  or  signify  all 
other  triangles. 

Certain  psychologists,  still  believing  that  the  image  must 
correspond  to  the  thing  it  signifies,  proposed  the  theory  of 
the  generic  image.  The  generic  image  is  supposed  to  be  a 
"general  image" — a  composite  of  all  the  characteristics  of 
the  particular  individuals  in  a  class — a  composite  photo- 
graph, so  to  speak.  Accordingly,  the  generic  image  is 
thought  to  have  a  "distinct  and  salient  centre  or  core  cor- 
responding to  the  common  characteristics  of  a  class,  together 
with  a  vague  and  inconstant  margin  corresponding  to  the 
variable  characters  of  the  individuals  composing  the  class."1 

The  generic  image,  therefore,  is  a  form  of  the  copy  image, 
but  as  such  it  is  wholly  inadequate,  as  we  have  pointed  out. 
What  would  be  the  character  of  the  generic  image  of  color? 
The  writer  has  never  been  able  to  observe  a  generic  image 
in  his  own  consciousness.  Hazy,  sketchy,  and  indistinct 
images  of  some  particular  object,  or  images  constructed  out 
of  the  re-presentations  of  parts  of  different  objects  of  the 
same  class,  he  has,  but  such  images  are  not  generic  images. 

1  Baldwin's  "Dictionary  of  Philosophy  and  Psychology,"  article  on  Generic 
Image. 


CONCEPTION  307 

After  all,  the  generic  image  is  not  necessary.  Any  image 
can  be  the  bearer  of  meaning.  Most  of  the  images  we  use 
in  thinking  are  verbal  images  and  they  bear  no  resemblance 
to  the  things  they  stand  for.  We  have  already  seen  in  the 
chapter  on  imagination  that  there  is  an  increasing  tendency 
to  give  up  concrete  copy  images  and  use  word  images  instead. 

Not  only  images,  but  also  perceptions  may  serve  to  sig- 
nify meaning.  The  perception  of  a  certain  shell  may  in  the 
geologist's  mind  signify  the  characteristics  of  a  whole  geo- 
logical age,  provided  his  attention  is  centred  on  its  meaning 
and  not  on  its  sensory  appearance. 

Consciousness  of  Meaning. — The  important  part  of  the 
concept  is  consciousness  of  fneanine.  When  we  see  or  hear 
the  words  "chair,"  "table,"  "book,"  we  understand  what 
they  mean,  although  we  may  not  consciously  re-present  any 
one  of  the  concrete  things  named.  The  content  of  con- 
sciousness is,  in  each  instance,  made  up  of  the  word  and  its 
meaning.  If,  on  the  other  hand,  we  should  see  or  hear  the 
words  "elbat,"  "koob,"  "riahc,"  we  do  not  understand 
them.  There  is  practically  no  consciousness  of  meaning, 
nothing  but  the  sensory  aspects  of  the  words. 

Whenever  an  image  or  percept  stands  for,  signifies,  sym- 
bolizes something  that  is  not  present  as  a  sensory  content, 
the  "standinjrjor,"  "signifying,"  "symbolizing"  is  conscious- 
ness .of  meaning..  The  word  "book"  arouses  a  definite  group 
of  meanings,  which  are  marked  off  in  the  mind  from  all  other 
meanings.  The  word  "dog"  arouses  a  different  group. 
And  so  each  symbol  of  meaning  turns  consciousness  in  a  cer- 
tain direction,  and  gives  an  added  content  to  consciousness. 
This  content  (meaning)  cannot  be  described,  for  it  dQe_s_np.t 
exist  in  sensory  terms,  but  rather  in  terms  of  relation.  That 
it  is  a  conscious  content  which  gives  a  determining  character 
4o  the  concept  may  be  shown  in  various  ways.  For  instance, 
suppose  I  should  pronounce  the  word  "bear."  Your  mind  is 
turned  immediately  toward  a  class  of  wild  animals.  But 
suppose  that,  while  this  meaning  is  hanging  in  your  mind,  I 


PSYCHOLOGY 

the  words  "your  burdens  cheerfully";  you  would  then 
\  fC'yr^/know  that  you  had  aroused  the  wrong  meanings.     A  mental 
1 1  shock,  accompanied  by  the  feeling  that  the  animal  meaning 
'^&  not  appropriate  would  follow.     You  would  then,  while 
the  words  ("your  burdens  cheerfully")  were  still  upon  my 
lips,   change  the  meaning — turn  your  mind  in  the  proper 
direction.     This  experience  would  be  impossible  if  conscious- 
ness of  meaning  were  not  a  definite  mental  content. 

Now,  we  have  already  seen  that  no  moment  of  conscious- 
ness, with  the  possible  exception  of  the  pure.-  sensation,  is 
absolutely  isolated  and  free  from  meaning.  All  experience 
is  interwoven  by  the  threads  of  relationship.  Everything 
experienced  suggests  the  relations  it  may  have  to  other  things 
and  to  other  aspects  of  its  own  existence.  For  instance,  the 
momentary  perception  of  one  aspect  of  the  penknife  (its 
appearance  as  it  lies  on  the  table)  means  all  the  other  char- 
acteristics of  it  not  now  presented,  because  I  recognize  the 
knife  as  the  same  throughout  its  different  aspects.  Or  it 
may  mean  for  me  all  other  individual  members  of  its  class, 
because  I  recognize  a  certain  group  of  characteristics  as  the 
same  in  a  number  of  different  instances.  In  the  one  case, 
the  concept  is  individual  and  in  the  other  general.  The  im- 
portant point  to  be  noted  is  that  in  either  case  consciousness 
of  meaning:  is  bagfd  npr>n  th?  relation?  whi^h  exisUietw^n 
the  parts  of  pur  conscious  life.  When  attention  is  directed 
toward  the  relational  connections  which  a  thing  or  its  image 
has,  instead  of  upon  the  thing  itself,  we  are  conscious  of 
meanings.  The  definition  and  organization  of  these  mean- 
ings into  distinct  units  which  mark  off  classes  of  objects  is 
the  formation  of  the  concept. 

The  Intension  and  Extension  of  Concepts. — The  definite 
group  of  meanings  which  a  thing  or  term  has  for  us  is  known 
jas  its  intension.  For  example,  the  meanings  which  are  com-  , 
prehended  by  the  concept  "horse"  constitute  its  intension. 
The  use  of  this  meaning  to  mark  off  a  single  group  or  class 
of  separate  objects  constitutes  the  extension  of  the  concept. 


CONCEPTION  309 

Thus,  the  application  of  "horse  meaning"  to  all  individual 
members  of  the  class  "horse,"  constitutes  the  extension  of 
the  concept.  The  definition  of  the  concept  consists  in  set- 
ting out  clearly  the  meanings  which  are  embodied  in  it,  i.  e., 
in  making  its  intension  explicit.  It  is  plain  that  as  the  ex- 
tension of  a  concept  increases,  the  intension  is  restricted. 
The  intension  of  general  concepts  is  much  more  restricted 
than  is  the  case  in  individual  concepts.  The  meanings  which 
we  can  apply  to  a  number  of  different  individuals  are  fewer 
than  those  which  we  apply  to  a  single  individual. 

The  Genesis  and  Development  of  the  Concept. — The__h£.- 
ginning  oLthe  concept  is  laid  in  perception^  Just  as  soon  as 
a  presented  object  begins  to  suggest  qualities  and  attributes 
not  actually  presented  jto  the ;  senses;  it  begins. to_functiQH_a.s 
a__concept.  The  growth  and  development  of  the  concept 
continues  just  as  long  as  we  continue  to  get  new  experiences 
from  the  object.  After  we  have  experienced  an  object  many 
times  and  have  come  to  know  its  various  aspects,  any  single 
presentation  reveals  not  all  of  the  object  as  we  really  know 
it,  but  a  single  aspect  of  it.  All  its  other  aspects  are  either 
ignored  and  attention  given  to  the  object's  sensory  character 
at  the  moment,  or  they  are  given  as  meanings.  If  attention 
is  placed  upon  the  presented  sensory  content,  while  the  mean- 
ings occupy  the  background  of  consciousness,  the  mental 
state  is  perceptual.  But  if  the  presented  object  itself  is  a 
secondary  consideration  and  we  become  intent  upon  its 
meanings,  then  the  mental  state  is  conceptual.  For  in- 
stance, on  the  mantel  in  my  study  there  is  an  old  Pompeian 
lamp.  If,  as  I  look  at  it,  my  consciousness  is  confined  to  its 
form  and  color,  the  material  of  which  it  is  made,  and  the 
figures  carved  upon  it,  my  consciousness  is  perceptual.  But  !** 
if  when  I  look  at  it  I  feel  the  tug  of  a  hundred  thoughts  con-  , 
cerning  it  and  the  fated  city  it  represents,  striving  to  rise  to 
full  consciousness,  then  the  presented  object  is  merely  a 
symbol  for  a  whole  troop  of  meanings,  and  it  really  functions  ,  ^ 
as  a  concept.  If  we  could  follow  the  development  which  the 


310  PSYCHOLOGY 

consciousness  of  this  object  has  undergone  in  my  mind,  we 
should  have  the  history  of  the  development  of  an  individual 
concept. 

Hand  in  hand  with  the  development  of  the  individual 
concept  goes  the  development  of  the  general  concept.  We 
not  only  learn  to  know  a  single  object  in  all  its  various  as- 
pects,  but  we  also  learn  at  the  same  time  what  character- 
istics are  common  to  all  the  members  of  the  group  to  which 
it  belongs,  and  thus  we  form  the  general  notion.  We  should 
note  that  these  two  processes  go  on  together,  that  the  indi- 
vidual notion  and  the  general  notion  develop  at  the  same 
time — that  as  we  meet  different  individuals  of  the  same  class 
we  discover  more  and  more  the  particular  characteristics  of 
any  single  individual,  and  as  we  discover  new  characteristics 
in  the  individuals,  we  learn  more  about  the  class  as  a  whole. 

It  is  sometimes  assumed  that  our  general  concepts  origi- 
nate only  as  a  result  of  that  logical  process  of  thought  which 
starts  with  a  number  of  particular  objects,  analyzes  and  com- 
pares them,  abstracts  the  common  qualities  and  generalizes 
them  into  the  concept.  The  origin  of  the  child's  concept  of 
lamp  would,  according  to  this  assumption,  first  involve  the 
acquaintance  with  a  number  of  individual  lamps  and  require 
that  he  should  then  compare,  abstract,  and  generalize  before 
he  has  any  notion  of  lamps  in  general.  This  is  a  false  as- 
sumption. What  really  happens  is  quite  different.  In  his 
first  experiences  with  a  single  lamp  the  child  will  be  attracted 
by  some  striking  characteristic  (its  light-giving  quality). 
This  immediately  becomes  a  general  notion  which  he  uses  to 
interpret  other  cases.  For  instance,  he  may  call  the  moon 
a  lamp.  He,  therefore,  generalizes  from  the  very  beginning, 
using  what  he  has  gained  from  his  first  experience  as  a  stand- 
ard. His  notion  of  particular  lamps  and  his  idea  of  lamps 
in^  general  both  start  in  this  limited  experience  and  develop 
gradually  as  his  experience  is  extended.  The  young  child 
calls  all  men  "papa,"  or  his  first  sheep  "dog,"  showing  that 
he  has  crude  embryonic  concepts  from  the  first.  But,  refer- 


CONCEPTION  311 

ring  to  the  latter  illustration,  further  sheep  experience  may 
do  two  things  to  his  concept:  (i)  It  causes  him  to  notice  for 
the  first  time  that  his  own  dog  has  short  hair,  claws,  and  a 
long  tail,  thereby  increasing  the  intension  of  the  concept; 
(2)  it  restricts  the  extension  of  his  general  concept,  since 
afterward  he  may  not  include  sheep  in  it.  Further  modi- 
fication of  his  concept  takes  place  as  he  meets  other  dogs  of 
different  kinds.  His  experiences  with  bird-dogs,  hunting- 
dogs,  watch-dogs,  etc.,  all  modify  his  general  concept,  and 
at  the  same  time  bring  out  more  definitely  the  characteristics 
of  each  individual.  It  is,  therefore,  in  the  process  of  form- 
ing general  notions  that  the  child  gains  a  definite  knowledge 
of  particular  things,  and  it  is  his  contact  with  particular 
things  that  modifies  and  develops  his  general  notion. 

Now,  while  it  is  true  that  the  foundation  of  knowledge 
must  be  laid  in  first-hand  experiences  with  things  themselves, 
it  is  also  true  that  after  we  have  gained  a  store  of  meanings 
in  this  way,  we  may  extend  our  old  concepts  and  gain  new 
ones  through  creative  imagination,  when  guided  by  language 
descriptions  and  definitions.  I  may,  for  instance,  never  have 
seen  a  zebra  or  a  picture  of  one.  Nevertheless,  I  may  get  a 
fairly  accurate  concept  of  this  animal  from  my  readings  or 
from  the  descriptions  given  me  by  another  person.  Guided 
~by  oral  or  written  descriptions,  I  may  fill  in  the  sensory  de- 
tails by  concrete  imagination,  drawing,  of  course,  upon  my 
first-hand  experience  with  similar  objects  (horses,  ponies, 
mules)  for  the  material  of  my  ideal  construction.  These  ex- 
periences are  modified  and  reconstructed  into  my  idea  of 
the  zebra.  Many  of  our  concepts  are  formed  in  this  way.  . 
This  form  of  conceptual  growth  and  modification  requires  a/I  \ 
higher  stage  of  mental  activity  than  that  based  upon  per- 
ceptual experience. 

Still  a  higher  form  of  conceptual  development  and  modi- 
fication is  found  in  our  more  abstract  and  scientific  concepts, 
in  the  development  of  which  neither  perception  nor  concrete 
imagination  plays  any  important,  determining  part.  Such 


312  PSYCHOLOGY 

concepts  consist  of  relations  which  we  comprehend  by  means 
of  the  higher  thought  processes.  Our  concepts  of  infinity, 
law,  force,  atom,  are  illustrations.  They  are  developed  out 
of  our  knowledge  of  the  relations  existing  between  things, 
and  which  we  discover  through  the  processes  of  judgment 
and  reason. 

The  concept,  then,  is  the  outgrowth  of  experience,  in 
which  perceptual  and  imaginary  contact  with  things  and 
the  comprehension  of  relations  in  judgment  and  reason  are 
prominent  factors. 

Language. — From  the  nature  of  the  concept,  we  can  see 
very  plainly  the  need  of  a  system  of  signs  or  symbols,  to 
which  we  may  attach  our  meanings.  Every  concept  is  a 
group  of  meanings  which  requires  some  tangible  sensory  con- 
tent to  call  it  up  in  our  mind.  We  have  already  seen  that 
the  concrete  image  of  an  object  serves  in  some  instances  to 
arouse  its  meanings.  We  have  also  noted  the  tendency  in 
thinking  to  substitute  for  the  concrete  image  of  the  object 
the  image  of  the  word  which  stands  for  the  object.  And, 
further,  not  only  the  image  of  the  word,  but  also  the  actual 
perception  of  it  may  serve  as  a  symbol  of  our  meanings. 

Language  is  a  system  of  signs  which  we  use  to  mark  off 
meanings.  Every  word  we  use,  or  see,  or  hear,  or  image,  is 
a  symbol  of  something,  and  is,  therefore,  conceptual  in  na- 
ture. Thought  deals  with  meanings,  and  language_js_jthe 
instrument  of  thought — the  tool  by  which  we  handle  mean- 
ings. If  I  should  name  in  rapid  succession  a  half-dozen 
things  in  my  office:  chair,  pen,  book,  desk,  door,  table,  you 
would  in  each  instance  understand  what  I  mean — each  word 
would  arouse  a  definite  set  of  meanings  in  your  mind  without 
the  necessity  of  your  forming  an  image  of  any  one  of  the 
objects  named.  In  other  words,  you  have  entertained  a 
number  of  concepts.  The  mere  presence  of  these  uncon- 
nected  concepts  in  your  mind  does  not,  however,  constitute 
thinking.  But  if  I  should  put  some  of  these  concepts  to- 
getEer~in  such  a  way  that  my  words  express  a  relation  be- 


CONCEPTION  313 

tween  them,  then  thought  would  be  aroused.  Thus,  I  may 
pronounce  the  words:  "The  book  is  on  the  table  near  the 
door."  Now,  the  words  in  themselves  are  nothing  but  a 
series  of  bare  sensory  sounds — mere  symbols.  There  is  noth- 
ing in  the  sounds  that  you  hear  which  imitates  or  in  any 
other  way  gives  a  clew  to  the  condition  which  exists  in  my 
office.  The  words  are  merely  arbitrary  symbols  of  the  mean- 
ings which  arise  in  your  mind.  And  as  symbols,  it  makes 
no  difference  what  they  are,  so  long  as  we  all  agree  to  use 
the  same  symbol  for  any  given  meaning.  I  might  have  said 
just  as  well:  "Le  livre  est  sur  la  table  pres  de  la  porte,"  or 
"Das  Buch  ist  auf  dem  Tisch  nahe  der  Thiir."  I  might 
have  written  the  sentence  on  the  blackboard,  or  I  might 
make  use  of  the  deaf  and  dumb  alphabet,  or  if  it  were  possi- 
ble I  might  convey  the  thought  to  you  through  gestures  and 
natural  signs.  The  meaning  in  all  cases  would  be  the  same. 
Some  of  the  symbols,  however,  would  be  more  convenient 
and  expeditious  than  others.  And  in  the  last  case,  the  na- 
ture of  the  symbols  would  differ  in  principle  from  all  the 
preceding  cases.  In  trying  to  make  you  understand  by 
gestures  and  natural  signs,  I  am  necessarily  obliged  to  use 
the  primitive  method  of  imitative  or  concrete  imagery  in 
arousing  the  meanings  in  your  mind.  I  should  have  to  point 
to  this  book,  and  that  table,  and  that  door  in  this  room, 
and  then  by  gestures  try  to  make  you  understand  the  con- 
dition in  my  office.  In  all  the  other  instances,  the  words 
suggest  the  proper  meanings  without  the  necessity  of  your 
filling  in  by  concrete  imagination  as  you  do  in  this  case. 

From  the  psychological  point  of  view,  one  of  the  functions 
of  language  signs  is  to  arouse  meanings,  or  rather  to  symbol- 
ize  meanings  in_our_own_thought  processes-^to^communicate 
ideas  to  ourselves,  so  to  speak.  For  it  is  true  that  we  think 
very  largely  in  term's  of  wolds,  i.  e.,  we  use  visual,  or  audi- 
tory, or  motor  images  of  words  in  thinking.  As  an  instru- 
ment of  thought,  language  signs  sort  out  and  preserve  our 
meanings.  Figuratively,  we  may  say  that  a  word  is  a  pigeon- 


PSYCHOLOGY 


hole  into  which  we  pack  away  certain  definite  meanings 
which  we  may  use  later  by  merely  glancing  at  its  number. 
But  language  has  other  functions  —  the  communication  of 
meanings  to  others.  Each  word  that  I  use  arouses  the 
meanings  which  you,  through  your  past  experiences,  have 
attached  to  it.  Ijrja^jjhe^ejgj^direct  yourjthought  through 
language  signs.  As  an  instrument  of  communication,  lan- 
guage  fsTa  social  institution.  The  social  aspect  of  it  con- 

\  tributes  very  much  to  the  development  of  conceptual  thought. 
I  Each  individual  communicates  to  others  the  particular  mean- 

(  ings  which  his  experience  has  given  him,  so  that  in  the  end, 
any  given  language  symbol  comes  to  have  a  group  of  mean- 
ings, which  is  the  product  not  of  a  single  individual,  but  the 
result  of  the  co-operation  of  the  members  of  'a  social  group. 
A  word  when  used  as  a  means  of  communication  by  several 
individuals  becomes  a  clearing-house  of  meanings.  The  re- 
finement, organization,  and  development  of  meanings  which 
language  fixes  for  us  is  due  largely  to  social  influences. 

The  earliest  form  of  language  (using  the  term  in  its  broad- 
est sense)  is  the  language  of  natural  signs,  or  imitative  ges- 
ture. In  natural  signs,  the  symbol  must  have  something  in 
common  with  the  thing  symbolized,  as  when  barking  like  a 
dog  is  used  to  communicate  the  idea  "dog,"  or  when  one 
closes  his  eyes  to  signify  sleep,  or  points  to  the  clouds  to 
indicate  rain,  or  puts  the  hollow  of  his  hand  to  the  mouth 
to  make  known  the  fact  that  he  is  thirsty.  It  should  be 
noted  that  gestures  that  merely  point  out  objects  are  not 


£5  ,  really  language 


For  instance,  if  I  point  to  the  clouds 


'simply  to  call  your  attention  to  them  and  nothing  more, 
then  the  pointing  and  the  thing  pointed  out  are  not  really 
signs.  They  do  not  signify  anything  beyond  that  which  is 
present.  A  sign  or  symbol  must  stand  for  something  beyond 
itself  —  something  not  present.  It  must  imply  some  mean- 
ing  in  order  to  function  as  a  language  sign.  If,  however,  my 
pointing  to  the  clouds  is  for  the  purpose  of  signifying  rain, 
then  the  act  becomes  a  true  symbol.  Any  gesture  or  imita- 


CONCEPTION 


315 


tive  act  which  symbolizes  something  not  present  may  be 
considered  a  language  sign . 1 

But  natural  signs  are  cumbersome,  inconvenient,  and 
unmanageable,  since  they  must  consist  in  the  reproduction 
of  much  of  the  original,  sensory  content  of  experience.  Only 
by  imitating  the  sensory  appearance  of  things  are  natural 
signs  able  to  convey  an  idea  of  them.  This  is  at  times  im- 
possible. At  best  only  the  simplest  and  crudest  concepts 
and  only  those  not  too  abstract  can  be  represented  by  natural 
signs.  "To  make,"  says  Taylor,  "is  too  abstract  an  idea 
for  the  deaf-mute;  to  show  that  the  tailor  makes  the  coat, 
or  that  the  carpenter  makes  the  table,  he  would  represent 
the  tailor  sewing  the  coat,  and  the  carpenter  sawing  and 
planing  the  table.  It  is  difficult  or  impossible  to  represent 
by  natural  signs  what  is  common  to  all  kinds  of  making  in 
abstraction  from  what  is  specific  in  this  or  that  kind  of  mak- 
ing. But  if  we  use  a  conventional  sign,  such  as  the  words 
'to  make,'  the  difficulty  disappears."2 

The  first  primitive  attempts  to  communicate  ideas  by 
means  of  written  characters  show  the  same  tendency  to 
imitate  the  sensory  appearance  of  the  things  represented. 
Ideasjwere_communicated  by  pictures  (ideograms).  Thus,  a 
picture  of  a  horse  stood  for  the  idea  horse.  But  here,  also, 
the  picture  is  too  cumbersome  a  form  and  has  given  way  to 
the  conventional  written  word.  The  picture  was  found 
hopelessly  inadequate  for  representing  concretely  all  the 
different  aspects  of  an  object  and,  failing  in  this,  the  ideo- 
gram became  more  and  more  merely  a  conventional  sign  or 
symbol. 

It  is  a  significant  fact  that  we  find  even  yet  in  our  highly 
developed  conceptual  thought,  controlled  and  guided  by 
conventional  language  forms,  the  old  primitive  tendency  of 
the  natural  sign-language  to  imitate  in  thinking  the  objects 

1  Stout:  "Manual  of  Psychology,"  p.  471. 

2  Article  on  Language  Function,  Baldwin's  "Dictionary  of  Philosophy  and 
Psychology." 


316  PSYCHOLOGY 


and  events  which  form  the  basis  of  our  thoughts.  For  in- 
stance, the  copy  image  which  so  often  arises  in  our  minds 
s  is  analogous  to  natural  signs  in  this  respect;  only,  of  course, 
*  they  are  used  exclusively  in  our  private  thinking  to  represent 
ideas  to  ourselves.  Like  natural  signs  and  ideograms,  they, 
too,  have  given  way  to  symbolic  forms,  in  this  case  to  verbal 
images. 

A  similar  primitive  attempt  at  concreteness  manifests 
itself  in  the  QnomatojoeJ^c  tendency  of  language.  Such 
words  as  ding-dong,  clang,  jingle,  mew,  fizz,  purr,  pop,  coo, 
etc.,  are  plainly  attempts  to  get  as  much  concrete  sensory 
content  as  possible  into  the  symbols  of  our  thought.  These 
imitative  words  have,  however,  become  purely  symbolic,  for 
few  of  us  ever  image  the  sensory  content  which  we  symbolize 
when  using  the  words.  Hence,  the  word  ring  serves  the  pur- 
pose better  than  ding-dong  to  symbolize  the  ringing  of  a 
bell,  ^n  general,  we  may  say  that  the^more  a  w_ord  suggests 
concrete  content,  the  less  fitted  it  is  to  serve  as  a  symbol  of 
.meanings!  The  Sensory  content  aroused  Abends  to  draw  at- 
tention away  from  the  meaning  of  the  term. 

A  study  of  natural  language  signs  among  primitive  peo- 
ples, shows  that  signs  tended  to  lose  their  imitative  con- 
creteness and  to  become  more  and  more  conventional,  the 
more  they  were  used.  This  result  we  should  expect  as  a 
natural  psychological  tendency.  For,  as  the  power  of  think- 
ing develops,  attention  is  drawn  away  from  the  concrete 
character  of  the  symbols  of  thought  and  directed  more  and 
more  to  the  meanings  which  they  convey.  Also,  the  more 
a  natural  sign  is  used,  the  less  need  there  would  be  for  carry- 
ing it  out  completely  in  order  to  convey  the  idea.  There  is 
then  a  constant  tendency  to  abbreviate  them. 

Origin  of  Language. — Now,  among  the  natural  signs  were 
some  which  have  been  considered  the  beginnings  of  our  pres- 
ent conventional,  spoken  language.  We  refer  to  the  imita- 
tive, vocal  signs,  such  as  "bow-wow,"  "mew,"  etc.  But  the 
imitation  of  the  sound  which  an  animal  makes  to  signify  the 


CONCEPTION  317 

idea  of  it,  like  barking  to  convey  the  idea  of  dog,  is  in  prin- 
ciple a  form  of  imitative  gesture.  It  is  different  only  in  that 
it  involves  the  movements  of  tongue  and  other  vocal  organs 
instead  of  those  of  hand  and  arms. 

It  seems  reasonable  to  suppose,  then,  that  conventional 
language  may  be  traced  back  to  imitative  gesture.     Lan-1 
guage  in  the  broader  sense  must  have  found  its  origin_in| 
that  j>tage  of  mental  development  where  a  natural  sign  ofi 
any  kind  was  used  to  signify  something^  beyond  itselL    As- 
sumlng  the  ability  to  reproduce  imitative  gestures  and  imi- 
tative vocal  sounds,  or  the  instinctive  vocal  expressions  of 
emotion,  all  that  is  needed  to  make  them  serve  the  purpose 
of  communication  is  the  mental  power  of  imaging  the  past 
experiences  which  have  been  connected  with  the  gestures  or 
sounds. 

Just  as  soon  as  primitive  man  wjis  able  to  consciously  JV^/, 
represent  to  himself  the  experiences  which  were  associated      .  K\ 
with  a  certain  movement  or  sound,  it  was  a  simple  and  nat- 
ural thing  for  him  to  hit  upon  the  device  of  reproducing  the 
gesture  or  sound  for  the  express  purpose  of  suggesting  the 
experiences  to  others.     The  fact  that  he  could  exert  a  certain 
control  over  others  in  this  way  must  have  given  the  language 
impulse  a  strong  incentive  at  the  very  beginning. 

The  advantage  which  vocal  sound  has  over  visible  ges- 
tures as  a  means  of  communication  could  not  help  but  give 
it  the  lead.  Vocal  signs  can  be  communicated  in  the  dark. 
It  is  said  that  certain  primitive  peoples  can  communicate 
only  imperfectly  in  the  dark  with  each  other,  because  visible 
gesture  is  such  an  important  element  in  their  language. 
They,  therefore,  are  obliged  at  night  to  go  to  the  fire  to  talk 
to  each  other.  Vocal  signs  can  also  be  exchanged  between 
individuals  who  are  unable  to  see  each  other  because  of  in- 
tervening objects.  Moreover,  the  vocal  organs  are  able  to 
function  when  arms  and  hands  are  otherwise  occupied,  or 
injured,  or  bound.  A  still  more  important  factor  rests  in 
the  fact  that  the  vocal  organs  have  no  other  function  to  in-  // 


318  PSYCHOLOGY 

terfere  with  the  language  function.  These  are  some  of  the 
causes  which  have  contributed,  although  perhaps  not  con- 
sciously, to  the  selection  of  vocal  signs  as  the  material  of 
conventional  language. 

There  are  several  current  theories  concerning  the  origin 
of  vocal  language,  but  they  all  disregard  the  connection 
wjiich  conventional  language  has  to  the  primitive  language 
qf_yis?Ble  gesture!  The  "in^erjectional  Aheory~,''  nicknamed 
the  "pofiJT-pnoh  theory,"  supposes  that  vocal  language  origi- 
nated in  the  instinctive  emotional  expressions,  such  as  the 
cry  of  fear,  when  used  to  communicate  to  others  the  idea  of 
the  presence  of  an  enemy,  or  dangerous  object.  The  "ono- 
matojwetic  theory,"  or  "bow-wow  theory,"  places  the  origin  of 
language  in  the  imitation  of  some  characteristic  sound  which 
objects  make  to  indicate  the  idea  of  the  object,  as  when  one 
imitates  the  barking  of  a  dog  in  order  to  convey  the  idea  of 
the  dog.  The  ' '  fiathognomic  theory,' '  sometimes  spoken  of 
as  the  "c^ing-dong"  theory,  supposes  that  certain  objects  or 
events  forcecTout,  or  "rung  out,"  of  primitive  man  certain 
vocal  sounds  which  were  in  some  way  expressive  of,  or  har- 
monious with  and  appropriate  to  the  nature  of  the  object  or 
event;  and  that  such  sounds,  being  repeatedly  "rung  out" 
of  the  organism  by  these  objects  or  events,  finally  were  used 
to  signify  them,  and  so  formed  the  nucleus  of  vocal  language 
signs.  Such  a  word  as  "zigzag"  is  an  illustration.  There 
seems  to  be  a  peculiar  appropriateness  of  the  vocal  expression 
"zigzag"  to  the  course  of  a  zigzag  line.  The  change  in 
direction  of  the  line  is  sympathetically  expressed  by  the 
syllables  "zig"  and  "zag."  The  English  verb  suck,  German 
saugen,  French  sucer,  also  show  a  kind  of  harmony  between 
the  act  of  sucking  and  its  name.  The  verb  bubble  is  intrin- 
sically expressive  of  the  action  of  bubbles.  In  fact,  there 
are  in  all  languages  so  many  cases  of  the  close  affinity  between 
the  names  and  the  objects  or  events  which  they  stand  for, 
that  there  appears  to  be  some  ground  for  the  "ding-dong" 
theory. 


CONCEPTION  319 

But  in  all  these  theories  of  the  origin  of  vocal  language, 
there  is  at  bottom  the  principle  of  imitative  gesture,  which 
they  neglect.  This  is  evident  in  the  interjectional  and  ono- 
matopoetic  theories.  To  imitate  the  cry  of  fear  or  the  char-i  , 
acteristic  sound  of  an  object  is  really  a  vocal  gesture  which)! 
describes  some  feature  of  a  situation  or  object.  Even  in  the 
pathognomic  theory,  appropriateness  between  the  vocal  ex- 
pressions and  the  things  they  signify  consists,  as  Stout  has 
so  clearly  pointed  out,1  in  the  imitation  by  the  movements 
of  articulation  of  some  feature  of  an  object  or  event.  The 
principle  of  imitative  gesture  is  not  so  evident  here,  but  it  is 
nevertheless  present.  In  zigzag,  for  instance,  the  tongue 
moves  in  imitation  of  the  course  of  a  zigzag  line.  To  pro- 
nounce "suck"  one  must  partially  imitate  the  real  act  of 
sucking.  It  is  even  more  evident  in  such  a  word  as  "pucker." 
In  giving  expression  to  the  word  "bubble,"  the  lip  move- 
ments really  imitate  the  action  of  bubbling  substances. 

The  "ding-dong"  theory,  therefore,  proves  more  than  it 
intends  to  prove.    The  theory  is  valuable  just  because  |t 


points  out  the  fari  th^t)  in  +h*»  Kpgmnin^  gppprh  w«,s  not  only 


sound  but  movement,  and  that  even  here  the  movement  fnn}c 


fhp_fnrm  of  ifmfgfivft  gesture — gestures  ma.de  by  the  speech 
organs.  This  is  quite  as  true  of  the  "bow-wow"  theory. 
For  instance,  barking  to  imitate  a  dog  consists  not  only  in 
imitating  the  sound  of  the  dog,  but  it  imitates  the  move- 
ments of  the  dog — it  describes  by  imitative  gesture  the  visi- 
ble appearance  of  a  dog  barking.  By  consciously  imitating 
the  movements  of  a  barking  dog  with  the  head  and  mouth, 
one  will  discover  that  the  sound  "bow-wow"  is  really  caused 
by  the  gesture.  The  imitative  movements  will  force  a  vocal  II 
expression  which  is  a  kind  of  rudimentary  bark,  like  the  dog's  " 
bark.  The  spund  is  really  incidental  to  the  gesture.  All 
these  facts  lead  us  back  to  the  statement  made  in  the  begin- 
ning of  the  discussion  that  the  origin  of  language  may  be 
traced  back  to  imitative  gesture. 

1  "Manual  of  Psychology,"  pp.  484-486. 


320  PSYCHOLOGY 

The  origin  of  language  appears  to  exemplify  the  growth 
and  development  of  the  concept.  All  attempts  to  use  mean- 
ings in  our  thinking  begin  by  imaging  or  reproducing  some 
sensory  quality  of  the  thing  thought  of,  and  making  that 
the  symbol  for  the  thing.  This  is  essentially  the  principle  of 
imitative  gesture.  Gradually,  however,  the  tendency  to  im- 
itate gives  way  and  the  symbols  of  thinking  become  purely 
arbitrary  and  conventional. 

Thought  and  Language. — There  is  a  tendency  in  some 
quarters  to  hold  to  the  dictum:  "No  language,  no  thought." 
If  by  language  is  meant  only  the  verbal  forms  of  conven- 
tional language,  then  thought  may  take  place  without  lan- 
guage. We  have  already  seen  that  we  may  think  in  terms  of 
concrete  images.  We  may  think  of  the  relations  between 
things  by  using  the  things  themselves,  or  the  images  of  the 
things,  as  symbols  of  thought.  We  may  also  think  in  terms 
of  natural  signs  or  gestures.  It  is  true,  however,  that  thought 
requires  symbols,  and  words  are  the  most  serviceable  sym- 
bols. It  is  also  true  that  the  development  of  language  and 
the  development  of  thought  take  place  together,  and  that 
without  the  verbal  signs  of  oral  and  written  language  our 
systems  of  thought  could  never  have  reached  their  present 
stage  of  perfection.  There  is  no  reason  to  suppose,  however, 
that  in  the  absence  of  the  invention  of  words  thought  would 
have  been  impossible.  n  *  + 

^j^J^AuL  &**+ 


JUDGMENT 

Judgment  and  Perception. — We  have  already  pointed  out 
the  fact  that  every  act  of  perception  involves  a  rudimentary 
form  of  judgment.     Perception  contains  the  recognition  of 
whatever  is  presented  to  the  senses  as  similar  to^  or_identical 
with,  objects  we  have  known  before.     In  this  act  of  recogni-  » 
tion  there  is  an  implicitly  experienced  relation  j)f_identity  I 
between  the  sensory  presentation  and  past  contents  of  con-  | 
sciousness.     If  our  view  of  perception  is   correct,  we  may 
suppose  that  in  the  baby's  early  stages  of  development  each 
perception  of  its  nurse  involves  a  vague  and  undifferentiated 
experience:    "TMs-thing-that-I- now -see-is-the-same- thing  - 
that-has-bathed-and-clothed-me-before."     Irrperceptioii  the 
relation_jgf  JJjie__Bresent  jensorycontentto  past  experiences 
is  not_expjicitly  experience^     Thiscontent  Is  merged   so 
completely  into  the  unity  of  perception  that  the  rudimentary 
judgment  involved  does  not  come  to  the  surface  of  conscious- 
ness.    In  judgment,  on  the  other  hand,  the  relation  between 
our  mental  contents  of  consciousness  is  explicitly  experienced        i      . 
and  attended  to.     We  may,  therefore,  define  judgment  ten-  /Mjr*^ 
tatively  as  the  consciousness  of  relation  between  our  mental       5 
contents^.  In  so  far  as  perception  involves  the  relation  of 
one  mental  content  to  another,  it  is  the  beginning  of  judg- 
ment.   In  taking  up  the  discussion  of  judgment  we  are, 
therefore,  not  introducing  a  totally  new  process. 

The  Nature  of  Judgment. — Popular  thought  about  judg- 
ment is  based  almost  entirely  upon  the  logical  treatment  of 
judgment.  Th§  logician  js  intejrested^jprimarily  in  the  lan- 
guage expression j)fj:houffht-  He  therefore  defines  judgment 
as  the  expressed  relation  between  two  concepts.  In  formal  logic,  * 

321 


322  PSYCHOLOGY 

a  judgment  is  a  proposition  containing  a  subject  and  a  predi- 
cate, with  a  copula  to  conjoin  them.  Two  terms  verbally 
joined  to  show  a  relation  between  the  terms — that  is  the 
judgment  of  logic.  For  the  logician  the  printed  or  spoken 
sentence,  "Iron  is  a  metal"  is  a  judgment,  and  is  thought 
of  and  treated  independently  of  the  real  conscious  experi- 
ence which  is  back  of  it.  In  psychology,  on  the  other  hand, 
we  are  concerned  with  the  conscious  states  themselves— the 
actual  mental  processes  that  take  place  when  we  form  judg- 
ments. Psychologically,  judgments  may  or  may  not  be  ex- 
I pressed  in  language  terms.  And,  moreover,  the  language 
form  of  a  judgment  may  not  adequately  represent  the  mental 
process  itself.  We  must  therefore  observe  the  actual  con- 
scious states  in  order  to  get  at  the  nature  of  judgments. 

Judgment  as  Apperception. — Psychologists  are  not  all 
agreed  in  their  definitions  of  judgment.  It  has  been  sug- 
gested by  Kant  that  judgment  is  simply  the  entrance  into 
consciousness  of  any  presented  mental  content.  He  assumes 
that  no  presented  content  can  become  clear  in  consciousness 
until  it  has  been  received  by,  and  assimilated  to,  an  organized 
body  of  knowledge  already  in  the  mind.  He  says:1  "I  find 
that  a  judgment  is  nothing  but  the  mode  of  bringing  a  given 
cognition  into  the  objective  unity  of  apperception."  The 
" objective  unity  of  apperception"  here  means  the  organized 
body  of  past  experiences  in  the  light  of  which  any  given 
presentation  is  understood  or  interpreted.  For  instance,  on 
seeing  a  rose  I  have  an  experience  which  when  expressed  be- 
comes: "That  is  a  rose."  In  order  to  be  clearly  conscious 
of  the  rose,  the  presentation,  or  sensations  which  I  get  from 
the  presented  object  must  be  referred  to  that  which  I  have 
previously  learned  about  roses.  TJl±_2C"TlMriirig  fff  th1'^™" 
vjouslv  organized  knowledge  with  the  presentation  is,  accord- 
ing to  Kant,  the  judgment.  The  judgment  is,  thereforefin 
this  case  the  conscious  reaction  to  a  group  of  sensory  presen- 

1  "Critique  of  Pure  Reason,"  Supplement  14,  Sec.  19,  Max  MUUsr's  transla- 
tion. 


JUDGMENT  323 

tations,  by  virtue  of  which  the  presentations,  or  entering 
cognitions,  are  properly  placed  and  incorporated  into  the 
knowledge  I  already  have.  This  view  of  judgment  is  in 
accord  with  that  in  the  preceding  discussion  of  judgment 
and  perception.  It  was  there  pointed  out  that  the  process 
of  apperception  is  fundamentally  a  rudimentary  judgment. 
If  we  follow  out  Kant's  view  critically,  the  judgment  "That 
rose  is  red"  contains  two  judgments.  The  language  expres- 
sion of  the  double  psychological  process  would  be:  "It  (the 
presented  thing)  is  a  rose,"  and  "The  rose  is  red."  The 
presentation  is  apperceived  (judged,  according  to  Kant)  both 
as  a  rose  and  as  red.  This  example  furnishes  an  illustration 
of  the  difference  between  the  language  form  of  judgment 
(logic)  and  the  mental  process  (psychology)  back  of  it.  The 
judgment  "That  rose  is  red"  is  for  logic  a  single  judgment 
because  the  logician  neglects  the  actual  conscious  processes 
involved  in  bringing  each  term  of  the  logical  judgment  to 
consciousness.  Each  single  term  of  the  logical  judgment  is  I  ^* 

(tjiejresult  of  jinjimplicit  judgment  which  does  not  show  itself/ 
in  language  expression. 

Judgment  as  iJelief. — Another  view  makes  judgment  the 
conscious  act  of  acceptance  which  we  give  to  a  sensory  pres- 
entation or,  indeed,  to  any  other  mental  content.     According 
to  this  view,  judgment  is^a  positjye  Attitude  of  assent  pr  beliej[.m 
Conscious  content  that  does  not  gain  this  assent  fails,  there- 
fore, to  develop  into  judgment.     Judgment  is  something  more 
than  the  entrance  of  a  given  content  into  consciousness.   Jt_ 
is  an  attitude  which  we__take__toward-the  content.     The  atti-  . 
/  tucle  of  belief  is,  accordingly,  the  true  form  of  psychological  ) 
)  predication.     In  this  connection  we  should  note  that  the  so- 
called  negative  judgments,  or  judgments  of  disbelief,  are  neg- 
ative only  in   the  form  of  the  language  expression.     The 
judging  attitude  itself  is  always  a  positive  one.     For  instance, 
on  seeing  a  counterfeit  bill,  I  may  exclaim:  "It  is  not  good." 
The  judgment  here  consists  in  my  acceptance  of  the  pre- 
sented content  "not  good."     This  acceptance  is  psychologi- 


324  PSYCHOLOGY 

cally  a  positive  attitude,  although  the  expressed  form  is 
negative.  The  judgment  involved  in  the  sentence  "The 
table  is  not  round"  is  my  positive  acceptance  of  "not-round- 
ness"  as  an  attribute  of  the  table.  Psychologically  there  are 
no  negative  judgments  any  more  than  there  are  negative 
perceptions,  or  images,  or  memories.  It  is  only  from  the 
logical  point  of  view  that  judgments  may  be  called  negative, 
and  then  only  because  of  their  external  form. 

What  distinguishes^ judgment^from^  mere  associatioQs^gf 
mental  contents  ?  Some  recent  investigators  of  the  processes 
oi^u^g^nentcontend  that  the  distinctive  judging  process  is 
the  acceptance  or  rejection  of  conscious  content  presented 
to  the  mind  as  a  solution  to  some  problem.  The  problem 
may  be  consciously  formulated,  as  when  we  look  at  a  fabric 
in  order  to  determine  its  color.  Cognitive  curiosity,  or  in- 
terest in  the  existence  or  non-existence  of  things  may  be 
sufficient  to  supply  the  problem.  Accordingly,  acts  of  judg- 
ment will  arise  whenever  problems  (implicitly  or  explicitly 
formulated)  are  set  in  consciousness,  and  whenever  the  con- 
tents supplied  by  association  are  received  as  satisfying  or  not 
satisfying  the  requirements  of  some  intention  of  conscious- 
ness. The  intention  or  problem  may  involve  the  question 
of  whether  a  certain  state  of  affairs  is  or  is  not  true.  This 
view  of  judgment  is  similar  to  the  view  which  looks  upon 
judgment  as  belief.  They  both  presuppose  that  conscious 
content  may  be  poised  or  held  in  consciousness  without  ac- 
ceptance or  rejection.  Accordingly,  consciousness  is  sup- 
posed to  have  a  twofold  character — that  of  conscious  act 
and  that  of  conscious  content.  Judgment,  then,  is  the  act 
of  acceptance  or  rejection  of  conscious  content. 

Judgment  as  the  Ascription  of  Meaning. — Still  another 
view  of  judgment  considers  it  to  be  the  mental  act  of  ascrib- 
ing meaning  to  whatever  presents  itself  to  consciousness  for 
interpretation  or  comprehension.  This  view  has  much  in 
common  with  the  view  that  judgment  is  a  form  of  apper- 
ception. For  it  is  plain  that  whatever  meaning  is  ascribed 


JUDGMENT  325 

to  a  thing  depends  upon  the  nature  of  our  past  experiences 
— upon  the  character  of  the  organized  systems  of  knowledge 
which  have  been  previously  developed  in  the  mind.  In  other 
words,  we  judge  (ascribe  meaning  to)  a  new  situation  in  the 
light  of  past  experience.  When  a  given  stimulus  presents 
itself,  the  mental  act  of  giving  it  meaning  is  an  act  of  apper- 
ception. In  a  large  number  of  cases,  the  presented  object 
(the  given)  and  its  meaning  are  so  closely  and  immediately 
united  that  the  act  of  relating  them  is  really  a  perception — 
a  direct  apprehension.  The  synthesis  of  the  given  and  its 
meaning  is  so  immediate  that  the  distinction  between  them 
is  not  evident.  But  in  other  cases  the  meaning  does  not  fol- 
low as  closely  upon  the  heels  of  the  given.  Just  what  the 
presented  object  is,  or  what  its  functions  and  attributes  are 
— in  other  words,  what  its  meaning  is — is  not  immediately 
grasped.  It  is  then  necessary  to  search  for  and  find  a  mean- 
ing which  can  be  ascribed  to  the  given.  This  mental  act  is 
much  more  plainly  a  judgment.  However,  the  jiifference^m 
the  two  classes  of  cases  may  turn  out  to  be  only  a  difference 
in  the  immediacvofthesynthesis  ofJJiejriven  and  its  mean- 
ing. If,  for  instance,  a  familiar  object  with  a  seat,  four  legs 
and  a  back  are  presented  to  my  senses,  I  immediately  appre- 
hend (perceive)  it  as  a  chair.  But  if,  on  the  other  hand,  an 
unfamiliar  object,  with  three  legs  supporting  a  tilted  board 
upon  which  is  mounted  a  large  wooden  wheel,  is  shown  to 
me,  I  am  for  the  moment  unable  to  place  it  in  my  mind.  I 
should  then  be  obliged  to  search  for  a  meaning  to  give  it  be- 
fore I  could  understand  the  thing.  If  I  were  acquainted 
with  early  colonial  customs,  I  should  then  recognize  it  as  a 
spinning-wheel.  In  the  one  case,  the  meaning  comes  without 
delay  and  is  not  sundered  from  the  given.  In  the  other  case, 
the  meaning  is  delayed  and  is  consciously  united  with  the 
given.  In  one,  the  meaning  is  implicitly,  and,  in  the  other, 
explicitly,  ascribed.  However,  according  to  the  view  we  are 
discussing,  both  cases  are  fundamentally  the  same,  and  are, 
psychologically,  judgments.  Even  granting  the  soundness 


326  PSYCHOLOGY 

of  this  view,  it  would  be  more  convenient  and  less  confusing 
to  apply  the  term  judgment  only  to  those  cases  where  mean- 
ing is  explicitly  ascribed  to  whatever  is  presented  to  con- 
sciousness, thus  allowing  the  term  perception  to  include  all 
cases  of  direct  apprehension.  Such  a  distinction  would  be 
in  accord  with  the  point  of  view  taken  in  the  beginning  of 
this  chapter. 

Judgment  as  Comparison. — A  view  of  judgment  which  is 
older  than  any  so  far  mentioned  is  the  one  that  considers 
judgment  as  involving  the  process  of  comparison.  We  judge 
when  we  compare.  Or,  to  turn  the  statement  about,  in 
order  to  judge  we  must  compare  two  presentations,  ideas, 
or  concepts,  and  mentally  assert  some  relation  between  them. 
Thus  we  form  judgments  when  we  compare  two  weights  and 
decide  whether  they  are  alike  or  different  in  weight.  It  is, 
of  course,  true  that  we  may  make  judgments  in  this  way, 
but  judgments  are  certainly  not  limited  to  acts  of  compari- 
son. Judgments  which  assert  existence,  as  "There  are 
twelve  months,"  and  impersonal  judgments,  as  "It  rains," 
do  not  involve  comparison.  Even  where  judgment  by 
comparison  is  possible,  careful  observation  has  shown  that 
it  may  take  place  without  comparison.1  For  instance,  in 
the  experiment  of  judging  the  likeness  or  unlikeness  of 
two  weights,  it  would  seem  that  when  the  subject  lifts  the 
second  weight  he  must  recall  the  impression  made  by  the 
first  weight  and  compare  it  with  that  of  the  second  weight 
in  order  to  judge  whether  the  second  weight  is  the  same 
or  different.  •  But  investigators  have  reported  that  no  recol- 
lection of  the  first  weight  need  be  present  when  the  judgment 
is  made.  The  second  weight  is  therefore  not  consciously 
compared  with  the  first  weight.  The  judgment  of  "same" 
or  "different"  is  made  immediately  upon  the  impression  pro- 
duced by  the  second  weight  without  any  conscious  recall  of 
I  the  first  weight.  The  first  weight  leaves  a  conscious  "set" 
or  adjustment  which  prepares  for  the  judgment  and  when  the 
1  Schumann,  "Zeitschrift  fur  Psychologic,"  1898,  XVII,  119. 


JUDGMENT  327 

second  weight  is  lifted  the  judgment  of  "same"  or  "different" 
is  made  without  any  conscious  reference  to  the  first  weight. 
Thg  judgment  in  such  cases  depends  of  course  upon  t^g, 
nature  of  pasT"experience  (the  experience  of  the  first  weight) , 
buFit  is  not  the  resulfof  conscious  comparison  of  the  first 
weight  with  the  second  weight.  The  judgment  comes  as 
immediately  and  directly  as  the  recognition  of  a  familiar 
object.  Every-day  experience  furnishes  many  illustrations 
of  judgments  which  might  follow  the  process  of  conscious 
comparison  but  which  actually  take  place  without  it.  On 
meeting  a  man  over  six  feet  in  height  we  immediately  form 
the  judgment — "very  tall" — "taller  than  usual,"  without 
consciously  recalling  and  representing  to  ourself  the  heights 
of  other  men  and  comparing  the  presented  individual  with 
those  we  recall.  We^  are  alrea^y^pr^p^ed^bv^ojir^pasj;  ex- 
perience  to  form__tne ^  Ju7lgment_directly,  without  conscious 
recall  and  without  comparison.  Thus  in  the  illustrations 
we  see  that  the  judging  process  may  approach  that  of  imme- 
diate apprehension  or  perception,  which  is  essentially  the 
entrance  of  the  given  into  a  predeveloped  system  of  knowl- 
edge. 

Judgment  as  Evaluation. — A  popular  way  of  considering 
judgment  looks  upon  it  as  a  process  of  evaluation.  When 
a  given  presentation  is  evaluated  according  to  some  stand- 
ard, the  mental  process  is  that  of  judging.  Thus  the  stock- 
man judges  the  weight  of  a  fat  steer.  The  standard  by 
which  he  judges  is  that  which  he  has  formed  in  his  former 
experience  with  cattle.  The  judge  on  the  bench  after  hear- 
ing a  case  renders  judgment,  i.  e.,  gives  a  sentence,  corre- 
sponding to  the  offense  or  fixes  the  damages  in  accordance 
with  the  losses  sustained.  In  both  instances  a  given  presenta- 
tion or  situation  is  evaluated  by  referring  it  to  a  standard. 
The  standard  of  judgment  may  be  in  certain  cases  consciously 
represented,  and  the  given  presentation  compared  with  it.. 
The  judgment  is  then  formed  as  a  result  of  the  comparison. J 
Or,  on  the  other  hand,  the  standard  may  not  be  consciously 


!l 


328  PSYCHOLOGY 

represented  when  the  judgment  is  made.  We  have  here 
the  same  mental  process  that  we  find  in  judgments  of  abso- 
lute pitch.  Those  few  musicians  who  possess  the  power  of 
absolute  pitch  have  formed  such  close  associations  between 
the  different  musical  tones  and  their  names  that  when  they 
hear  a  tone,  its  name  immediately  arises  in  consciousness. 
Likewise  the  stockman  in  his  extended  experience  with  cattle 
has  formed  close  associations  between  their  visual  appearances 
and  the  scale  of  weights.  When  a  certain  size  and  form  is 
presented,  his  judgment  of  weight  takes  place  immediately 
without  reference  to  a  dearly  defined  standard.  In  such 
cases  judgment  is  merely  a  sequence  of  mental  states  which 
may  be  likened  to  the  association  of  ideas. 

Because  of  perfect  familiarity  gained  through  extended  ex- 
perience hi  a  certain  field  of  knowledge  a  given  presentation 
may  call  up  immediately  its  evaluation  without  the  mediation 
of  the  standard  of  judgment  which  was  earlier  an  essential 
element  in  the  process.  The  expert  bank  teller  judges  a  bill 
to  be  good  or  bad  immediately  without  consciously  repre- 
senting to  himself  his  standard  of  judgment.  On  the  other 
hand,  many  judgments  of  evaluation  are  made  only  after  the 
given  presentation  is  referred  to  and  compared  with  a  men- 
tal standard  which  is  consciously  represented  at  the  time  of 
judgment. 

There  is  a  tendency  in  certain  quarters  to  base  judgments 
of  evaluation  on  the  feeling  processes.  It  has  been  said 
with  some  degree  of  truth  that  the  judgments  of  value 
which  we  pass  upon  the  facts  and  events  of  life  depend 
not  so  much  upon  the  rational  ordering  of  mental  contents, 
as  upon  the  personal  choices  determined  by  our  feelings. 
Consequently,  to  approach,  or  appreciate,  reality  we  must 
"feel"  it,  or  in  a  way  "live"  it.  The  judgments  which  we 
form  concerning  the  value  of  works  of  art  (aesthetic  judg- 
ments) are  used  as  illustrative  of  all  judgments  (evaluation). 
We  evaluate  a  painting  or  an  opera  only  when  it  appeals  to 
our  feelings.  There  is,  therefore,  an  emotional  standard  for 


JUDGMENT  329 

such  judgments.  According  to  this  point  of  view,  the  basis 
for  our  estimation  and  appreciation  of  values  lies  deeper 
than  our  formulated  knowledges.  There  is  no  doubt  of  the 
fact  that  the  feelings  do  modify  the  cognitive  processes  to  a 
marked  degree,  but  we  cannot  admit  that  the  feelings  form 
an  independent  and  distinct  ground  of  judgment.  Where 
the  cognitive  standards  for  evaluation  are  not  plainly  evident 
it  is  very  probable  that  the  standards  of  evaluation  are  to  be 
found  among  former  cognitive  experiences  which  have  been 
thoroughly  assimilated  and  submerged  into  our  personality. 
In  whatever  way  we  may  consider  judgment  —  whether 
(i)  as  the  entrance  of  a  given  presentation  into  consciousness, 
or  (2)  as  belief,  or  (3)  as  the  ascription  of  meaning  to  the  given, 
or  (4)  as  comparison,  or  (5)  as  evaluation  of  the  given,  the 
^ 
~ 


entering  Content.  The  judging  process  is  best  tyj>ified_by^  the 
view  that  j'udgmentjs_the  ascription  of  meaningjbo  thejgiven.^ 
The  entrance  into  consciousness  of  any  given  presentation 
is  identical  with  that  of  ascription  of  meaning.  The  reac- 
tion of  consciousness  takes  place  only  when  the  given  pres- 
entation enters  consciousness  and  is  at  the  same  time  inter- 
preted in  the  light  of  some  mental  standard  which  has  grown 
up  through  past  experiences.  Belief  also  may  be  considered 
as  intimately  connected  with  the  entrance  of  the  given  into 
consciousness  if  not  part  and  parcel  of  the  same  process.  Be- 
lief is  a  mode  of  conscious  reaction,  determined  by  standards 
of  past  experience.  I  cannot  see  how  any  given  presentation 
can  enter  consciousness  without  involving  some  degree  of 
belief  or  disbelief. 

We  have  already  seen  that  comparison  may  be  and  usu- 
ally is  an  immediate  conscious  reaction  upon  the  second  term 
of  the  comparison  without  the  formal  representation  in  con- 
sciousness of  the  first  term.  The  judgments  "longer," 
"shorter,"  "brighter,"  "smaller,"  etc.,  may  be  direct  and  * 
immediate  conscious  reactions  made  at  the  instant  the 


33O  PSYCHOLOGY 

second  of  two  objects  is  presented.  This  has  been  demon- 
strated in  the  experiment  of  lifted  weights.  Evaluation, 
too,  results  from  the  direct  and  immediate  reaction  of  stand- 
ards of  experience  awakened  by  entering  contents  of  con- 
sciousness. Sometimes  this  reaction  of  consciousness  is 
merely  that  of  simple  apprehension  in  which  the  content 
already  in  the  mind  is  not  formulated  and  attended  to. 
•^1  In  such  cases  we  have  impjicit  judgments.  In  judgments 

Uj/A^Vproper,  however,  the  standards  by  which  we  interpret  the 

.j/rj  ^itering_contenFare^onsciously  formulated  and  attended  to. 

»jr^*  In  this~~case  there  Is  a  dual  act  of  attention.     Attention  is 

\jf\r,  pivided  between  the  mental  contents.     This  division  of  the 

attention  brings  out  the  relation  between  the  contents  and 

^M  v-*\**  unines  them  into  a  single  whole. 

In  its  most  developed  form,  then,  judgment  is  the__proc- 
ess  of  consciously  relating  one  mental  content  to  another. 
Jndgmenj_i^Jjierpfnre  thp :  eYperienre^LielatJon  between— two 
mentajjcontents.  The  relation  may  be  of  any  kind  what- 
ever: relations_of  dependence,  substance  and  attribu^  cause 
andeffect,  whole  and  part,  samem^  and  difference  temporal, 


spatial,  etc.  The  "simplest  and  most  primitive  judgments 
are  one-term  judgments  such  as  the  interjectional  judgment, 
"Wolf!"  the  impersonal  judgments,  "It  rains,"  and  the  de- 
monstrative judgments,  "There  is  a  tree."  In  these  cases 
the  mental  content  by  which  we  interpret  the  given  is  not 
consciously  formulated,  and  for  this  reason  it  is  difficult  to 
differentiate  the  judgments  from  simple  perception.  Logi- 
cians have  always  had  trouble  with  these  judgments  for  the 
reason  that  in  logic  judgments  are  supposed  to  be  made  up 
of  two  terms — a  subject  and  a  predicate.  What  then  are 
the  terms  in  such  judgments  as  "It  snows,"  "Fire,"  "There 
is  a  tree"?  Psychologically  there  is  no  difficulty  when  we 
understand  thafthe  second  term  that  the  logician  is  looking 
for  is  theTfiental  standard  by  which  we  Interpret)  or  ascribe 
meaning  to  the  given  presentation. 

In  our  discussion  oi  judgment  as  the  entrance  of  a  given 


JUDGMENT  331 

presentation  into  consciousness,  ascription  of  meaning,  belief, 
comparison,  and  evaluation,  we  have  so  far  spoken  al- 
most entirely  of  one-term  judgments,  or  judgments  involving 
a  single  presentation  and  its  interpretation.  Now,  many  of 
the  judgments  of  the  logician,  having  two  terms  when  ex- 
pressed in  language  form,  are  psychologically  one-term  judg- 
ments.  The  interjectional,  the  impersonal,  and  many  ofi 
the  demonstrative,  and  assertative  judgments  consist  in  the* 
single  act  of  giving  rnpa.m'ng  tQ  a  given  presentation..  There 
are,  however,  many  two- term  judgments  in  the  psychological 
sense.  Thus  in  the  judgment,  "The  rose  is  red,"  there  are 
two  presented  contents  which  are  united  in  the  judgment. 
In  such  judgments,  in  addition  to  the  act  of  joining  the  two 
terms  through  some  explicit  relation,  there  are,  psychologically, 
two  interpretations,  or  judgments,  involved  which  are  not 
usually  considered  in  logic.  They  consist  of  the  entrance 
into  consciousness  of  the  two  presented  contents.  On  the 
other  hand,  it  is  the  relational  joining  of  the  two  presented 
contents  which  constitutes  the  judging  process  of  formal 
logic. 

Kinds  of  Judgments. — There  are  many  ways  of  grouping 
judgments.  Sometimes  the  character  of  the  mental  CQJI- 
tents  related  in  the  judgment,  and  sometimes  the_chaja£ter 
of  the  relationship  itself  between  the  contents  determines  the 
classification.  Even  the  form  of  the  language  which  expresses 
the  judgment  is  sometimes  used  as  a  basis  of  classification. 

Grammarians  and  logicians  speak  of  assertative  judgments, 
hypothetical  judgments,  and  disjunctive  judgments.  The  as- 
sertative  judgment  is  a  simple  assertion,  as,  "The  grass  is 
green."  The  hypothetical  judgment  is  an  assertion  subject 
to  a  given  limitation,  as,  "If  it  rajns,  he  will  get  wet."  The 
disjunctive  judgment  is  an  indeterminate  assertion,  naming 
two  or  more  possibilities  which  may  exist  in  relation  to  a 
given  subject  in  such  a  way  that  the  truth  of  one  excludes 
the  truth  of  all  the  others,  as,  "He  is  either  a  Democrat  or 
a  Republican." 


-^         332  PSYCHOLOGY 

Judgments  may  be  classed  as  individual^  judgments,  gejth 
\eral  judgments,  and  abstract  judgments  accordingly  as  they  deal 
•  with  a  single  thing,  a  group  of  things,  or  an  abstract  quality. 

Perception  judgments  are  judgments  made  about  things 
presented  to  the  senses.  They  may  take  the  form  of  inter  - 
jectimal^jydgments,  as  when  the  shepherd  boy  cries  out: 
/Jft  "Wolf!"  Or  they  may  be  impersonal  judgments,  as,  "It 
rains."  In  the  impersonal  judgment  the  field  of  perception 
is  taken  in  an  indefinite  manner  as  the  object  of  thought. 
On  the  other  hand,  when  attention  is  narrowed  to  one  par- 
^  ticular  point  in  the  field  of  perception  the  judgment  is  a 
istrjUi3i&_judgment,  as,  "That_js  a  tree."  Genetically 
the  interjectional  and  the  impersonal  judgments  are  primi- 
tive forms  of  judgment.  Perception  judgments  may  also 
)e  looked  upon  as  judgments  of  naming,  or,  judgments  of 
classification,  as,  "That  is  an  animal."  If  we  should  carry 
out  the  classification  suggested  we  have  not  only  judgments 
about  things  perceived,  but  judgments  about  things  remem- 
bered, things  imagined,  and  things  generalized  into  concepts. 

Among  judgments  of  comparison,  or  judgments  of  likeness 
and  difference  there  are  mediate_jiudgments  and  immediate 
judgments.  We  have  pointed  outthat  in  comparing  two 
lifted  weights  the  experience  of  lifting  the  first  weight  may 
be  kept  explicitly  in  mind  while  the  second  weight  is  being 
lifted,  and  compared  with  it.  In  this  case  the  resulting 
judgment  is  a  mediate  judgment.  On  the  other  hand,  when 
the  judgment  of  lighter  or  heavier  is  made  directly  without 
explicitly  recalling  the  impression  of  the  first  weight,  the 
judgment  is  an  immediate  judgment. 

Judgments  may  be  classified  according  to  the  kinds  of 
relationships^  which  subsist  between  conscious  contents. 
This  principle  if  carried  out  consistently  would  give  a  long 
list  of  judgments.  But  since  the  relationships  of  cause  and 
effect,  of  substance  and  attribute,  and  of  space  and  time 
occupy  a  large  part  of  all  thinking,  the  classification  of  judg- 
ment upon  this  basis  is  limited  to  judgments  of  cause 


JUDGMENT  333 

© 

effect,  judgments  of  substance  and  attribute,  and  judgments 
of  time^abzLspace.  Whenever  we  think  of  one  thing  or  proc- 
ess as  existing  or  taking  place  as  a  consequence  of  another 
thing  or  process  we  employ  the  judgment  of  cause  and  effect; 
as,  "Poverty  brings  misery."  Whenever  we  think  of  a  thing 
and  its  essential  quality  or  characteristic  we  employ  the 
judgment  of  substance  and  attribute;  as,  "The  ring  is  round." 
Judgments  of  time  and  space  are  expressed  by  such  words  as 
earlier,  later,  before,  after;  and  right,  left,  above,  below,  etc. 
Analysis  and  Synthesis. — Judgment  may  be  considered 
both  as  analysis  and  synthesis.  We  employ  judgments  in 
dissecting  relatively  total  experiences  into  the  different  con- 
stituents of  which  they  are  composed.  Thus  in  the  judg- 
ments, "The  grass  is  green"  and  "Circles  are  round,"  we 
are  analyzing  out  of  the  percept  in  one  case,  and  out  of  the 
concept  in  the  other,  elements  which  are  already  present  in 
our  consciousness  of  them.  They  are  therefore  analytic  judg- 
ments. On  the  other  hand,  we  employ  judgments  in  putting 
together  contents  of  consciousness  which  have  never  been 
together  before  or  which  are  not  obviously  conjoined  in 
our  consciousness  until  the  judgment  takes  place,  i.  e.,  we 
add  something  to  a  given  conscious  state.  Thus  in  the 
judgments,  "Grass  is  valuable"  and  "Circles  are  symbols 
of  eternity,"  we  are  adding  something  to  our  concepts  of 
grass  and  circles  which  was  not  previously  present,  and, 
evidently  not  contained  in  them.  They  are  therefore  syn- 
thetic judgments.  If,  however,  the  ideas  of  "value"  and 
"eternity"  were  already  parts  of  the  concepts  at  the  moment 
the  judgments  were  made,  the  judgments  must  be  considered 
as  analytic.  Whether  a  judgment  is  analytic  or  synthetic- 
depends  upon  what  is  in  consciousness  previous  to  the  judg- 
ment. If  in  the  judgment,  "Lead  is  heavy,"  we  suppose 
that  the  concept  of  lead  already  included  the  idea  of  heavi- 
ness as  a  constituent  part  of  it,  then  the  judgment  is  analytic. 
On  the  other  hand,  if  we  suppose  that  our  consciousness  of 
lead  did  not  at  the  tune  include  the  idea  of  heaviness  but  that 


PSYCHOLOGY 

two  contents  were  separate  elements  of  thought,  and 
were  united  by  the  judgment,  then  the  judgment  is  synthetic. 
Without  doubt  we  do  put  together  separate  mental  contents 
in  a  synthetic  way  and  note  relationships  of  which  we  were 
not  previously  aware.  On  the  other  hand,  relationships  of 
which  we  are  only  vaguely  cognizant  in  a  single  total  experi- 
ence, perceptual  or  ideational,  may  be  brought  to  the  focus 
of  consciousness  and  made  clear  in  the  analytic  judgment. 

In  judgments  of  perception  where  the  two  contents  of 
the  judgment  are  explicitly  presented  to  the  senses  the  proc- 
ess is  obviously  analytic,  as,  "The  paper  is  white."  But 
if  one  of  the  contents  is  supplied  out  of  past  experience,  i.  e., 
remembered,  the  judgment  is  synthetic,  as,  "The  paper  be- 
longs to  John."  In  this  case  we  are  adding  to  the  percep- 
tion a  content  not  explicitly  present  in  it. 

Sometimes  what  we  add  to  a  given  percept  or  concept 
may  come  not  from  specifically  remembered  past  experi- 
ence, but  from  generalized  knowledge,  or  general  truth. 
It  is  just  here  that  synthetic  judgment  passes  into  inference. 
If,  for  instance,  I  conclude  that  a  certain  piece  of  lead  which 
I  see  is  heavy,  not  because  I  remember  that  it  is  heavy,  but 
because  I  know  that  "All  lead  is  heavy,"  then  the  judg- 
ment is  an  inference — the  result  of  a  reasoning  process  de- 
pending upon  the  presence  in  the  mind  of  a  general  truth. 

Judgment^  therefore,  may  be  traced  from  apperception  to 
reason  through  gradual  changes'  in  the  explicitness  of  the 
relationship  involved.  In  the  perception  or  apprehension  of 
any  external  object  past  experiences  are  iwiptidJly  added, 
or  related  to  the  given  presentation.  The  object  is  apper- 
ceived,  or  received  into  the  organized  body  of  knowledge. 
This  process  is  a  primitive  form  of  judgment — an  implicit 
judgment.  In  the  synthetic  judgment  the  added  content 
is  explicitly  and  consciously  joined  to  the  present  content 
of  consciousness  through  memory.  In  inference  the  added 
content  comes  through  generalized  knowledge.1 

1  For  a  fuller  statement  see  Pillsbury :  "The  Psychology  of  Reasoning,"  pp. 
172-175. 


JUDGMENT  335 

From  the  genetic  point  of  view  judgment  is  an  analytic- 
synthetic  process.  It  is  by  means  of  judgments  that  we 
first  break  up  our  vague  total  experiences  into  definite  and 
distinguishable  parts  and  organize  them  into  systems  of 
related  knowledges.  The  baby's  world  is  at  first  a  vague, 
confused  mass  of  experience.  Judgment  begins  in  the  analysis 
of  this  total  experience  into  its  constituent  elements,  but 
at  the  same  time  these  elements  of  knowledge  are  synthe-  / 
sized  through  judgments  into  organized  systems  of  knowledge.  I 

Judgment  and  Concept.  —  If  we  examine  the  beginning  of 
concepts  we  shall  find  that  they  originate,  \n 


1 
juHgments,  or  vague  recognitions  of  relations  between  the 
parts  of  experience.     As  the  child  analyzes  his  hazy  experi- 
ences into  their  elements,  and  sees  the  relations  between  them 
more  clearly,  his  ideas  about  things  become  more  definite. 
Things  assume  meaning  for  him.     The  mental  activity  by 
which  he  clears  up  and  marks  off  his  world  of  things  into 
definite  groups  of  meaning  is  essentially  the  process  of  judg- 
ment.    Thus    "mother"    comes    to    mean    "to    feed,"    "to 
rock,"   "to  bathe,"  in  short,   all  forms  of  maternal  care; 
"ball"    means    "to    roll."     These    meanings,  however,  are 
based  upon  particular  recognition  of  relation  between  dif- 
ferent contents  of  his  experiences.     The  later  development  (\ 
of  his  concepts  is  brought  about  through  explicitly  formed  | 
judgments.     Each    new    characteristic    which    we    discover 
about  an  object  gives  a  new  meaning  which  is  straightway 
embodied   in   the   concept.     The   concept  grows,    therefore, 
both  by   the  addition  of  new  relationships  given   through 
judgments  and  by  the  clearing  up  of  all  relationships  which 
are  already  vaguely  present  in  our  experience.     Judgment  is,  )> 
therefore,   the  conscious  process  by  which  we  arrange  our  \| 
experiences    into    systems    of    knowledge    (concepts).     The 
concepj_^ien  becomes  a  series  of  potential  judgments,  any 
one  of  which  is  available  lor  use  whenever  needed  and  called 
for  by  the  context  of  consciousness  or  purposes  of  thought. 
Not  only,  then,  is  judgment  the  means  of  forming  con- 


336  PSYCHOLOGY 

cepts,  it  is  also  the  means  of  making  use  of  concepts  in  think- 
ing.   Erojnjjigj^chological  point  of  view  all  the  judgments 
making  up  a  concept  cannot  be  thought  of  as  actually  existent 
aT  any  one  moment.     It  is,  therefore,  only  for  convenience 
sake  that  we  sometimes  speak  of  a  concept  as  a  sum  of  judg- 
ments.    What  is  really  meant  is  better  expressed  by  speaking 
\  of  the  concept  as  a  centre  of  meaning  from  which  radiate  a 
1  series  of  possible  judgments,  only  one  of  which  can  become 
I  explicit  and  definite  at  any  one  instant  of  conscious  activity. 
Judgment  is  the  means  by  which  we  analyze  and  unfold  the 
developed  concept  and  transform  its  meaning  into  definite 
forms  for  use  in  thinking. 

Judgment  as  the  Fundamental  Cognitive  Activity. — Con- 
sciousness of  relation  is  a  fundamental  cognitive  experience^ 
Without  it,  consciousness  would  reduce  to  a  series  of  separate 
mental  flashes,  and  would  be  without  any  kind  of  continuity. 
To  be  sure,  some  schools  of  thought  have  denied  that  the  con- 
sciousness of  relation  exists.  Hume,  for  instance,  said:  "The 
stream  of  thought  is  not  a  continuous  current,  but  a  series  of 
distinct  ideas,  more  or  less  rapid  in  their  succession."  The 
old  intellectualists  also  denied  that  consciousness  of  relation 
can  be  a  content  of  consciousness.  They  held  that  no  such 
experience  can  be  found  as  a  content  in  consciousness.  In- 
stead of  consciousness  of  relationship,  they  substituted  an 
"act  of  pure  thought,"  above  and  entirely  different  from 
conscious  content,  which  unites  the  separate  sensations  and 
s,  and  gives  continuity  to  consciousness.  James,  on 
e  other  hand,  is  an  able  defender  of  consciousness  of  rela- 
tion as  a  content  of  consciousness.  He  likened  the  stream 
of  consciousness  to  the  movements  of  a  bird  in  the  tree  tops — 
an  alternation  of  flights  and  perchings.  The  resting-places 
correspond  to  the  substantive  contents  of  consciousness, 
(sensory  experiences  and  ideas)  and  the  flights  to  the  tran- 
sitive contents  (consciousness  of  relation).  We  have,  he 
said,  a  consciousness  of  "jincl"  and  ^iP*  and  "by'i  and 
"but"  quite  as  truly  as  a  consciousness  of  "blue"  or  "cold." 


i 


JUDGMENT  337 

There  is  in  my  mind  no  doubt  of  the  fact  that  sensory 
impressions  and  ideas  appear  in  consciousness  in  a  relational 
aspect,  and  that  the  consciousness  of  relation  is  a  necessary 
and  fundamental  constituent  of  conscious  activity.  From 
the  very  first  sensory  impressions  appear  as  similar  or  differ- 
ent from  preceding  impressions.  The  consciousness  of  differ- 
ence may  be  vague  and  indefinite,  but  if  it  were  not  present 
there  would  be  no  differentiation  of  sensory  experiences. 
Rudimentary  and  nascent  experiences  of  recognition  depend 
upon  the  i*el<iLiuiia.l  experiences  of  samenessf  nr  similarity. 
We  have  seen  that  perception  of  a  simple  object  involves 
some  degree  of  recognition  of  the  sensory  experiences  as  the 
/same  as,  or  similar  to  previous  experiences.  We  could  not 
apprehend  the  simplest  object  without  this  consciousness  of 
relationship.  The  experienced  connection  of  sensory  stimu- 
lation with  something  already  familiar  is  a  primitive  and 
implicit  form  of  judgment.  Perception  and  judgment  are 
therefore  different  stages  in  thesame  fundamental  conscious 
activity.  We  have  also  seen  that  the  concepts  are  both 
formed  and  made  use  of  in  thinking  through  the  instrumen- 
,  and  we  shall  see  later  that  reason  is  noth- 
mammdatio^ of  Judgments  iy|  ^  ffijfltfrmgl 
way._  From  the  simplest  direct  apprehensions  to  the  most 
complex  cognitive  activities  some  form  of  judgment  is  always 
present  and  fundamental. 

^*  A         f  jL  i 

«v\ 


CHAPTER  XV 
REASONING 

Inference.  —  It  was  stated  in  one  of  the  previous  chapters 
that  the  three  aspects  of  reasoning  are  conception,  judg- 
ment, and  inference.  These  are  not  separate  processes,  but 
interdependent  mental  activities  which  we  have  separated 
only  for  the  purpose  of  discussion.  Judgment,  as  we  have 
seen,  is  involved  in  the  concept,  and  we  shall  soon  see  that 
inference  and  judgment  are  but  different  stages  of  the  same 
process.  Indeed  it  is  difficult  at  times  to  distinguish  between 
judgment  and  inference.  Moreover,  just  as  the  line  between 
judgment  and  perception  is  psychologically  not  a  hard  and 
fast  one,  it  is  also  not  an  easy  matter  to  determine  just  how 
much  of  inference  is  contained  in  perception.  Helmholtz, 
for  instance,  looked  upon  perception  as  unconscious  infer- 
ence. 

Inference  js  the  jirocess  ofconsciouslv  adding  to_a  given 
presentation_or  Direct 


If  I  say  that  the  paper^before  me  is  white, 
it  is  evidenttnat  the  whiteness  is  present  in  the  presentation, 
and  that  I  am  not  transcending  what  is  given  in  direct  cogni- 
tion in  making  the  judgment.  But  if  I  say  that  the  paper 
will  burn,  I  am  supplying  something  not  contained  in  the 
present  presentation.  This  something  is  supplied  out  of 
my  past  experience  and  I  am  therefore  transcending  my 
direct  and  immediate  consciousness  of  the  object.  I  may 
infer  that  the  crystal  in  my  watch  will  break  if  it  drops  upon 
the  floor;  that  the  lead  paper-weight  upon  the  table  is  heavy; 
that  all  men  are  mortal,  etc.,  etc.  In  each  of  these  cases  I 
am  making  a  judgment,  and  at  the  same  time  there  is  present 
in  my  mind,  more  or  less  explicitly,  a  reason  or  ground,  for 

338 


REASONING  339 

the  thought  entertained.  We  may  say  very  crudely  that 
inference  is  judging  with  a  reason,  or  conscious  ground,  for 
each  judgment.  In  inference,  the  conscious  content  added 
to  the  given  presentation  is  accepted  because  of  some  felt 
reason,  or  ground  for  it.  For  instance,  I  add  to  the  presenta- 
tion of  that  paper-weight  the  thought  of  heaviness,  because  I 
am  at  the  moment  conscious  that  all  lead  is  heavy.  If  I 
had  in  mind  no  reason,  no  conscious  support  for  thinking  the 
paper-weight  heavy,  the  experience  could  not  be  called 
an  inference  proper,  but  simply  a  judgment.  ^ 

Inference  and  Perception. — We  said  that  inference  is  the 
process  of  adding  to  a  given  presentation  or  direct  cogni- 
tion something  not  obviously  contained  in  it.  Now,  ev- 
ery act  of  perception  goes  beyond  the  sensory  presentation 
and  adds  content  not  present  to  the  sensed.  For  instance, 
when  I  perceive  the  paper-weight  on  the  table,  my  experi- 
ence of  the  object  depends  upon  more  than  that  given  in 
direct  cognition.  How,  for  instance,  can  I  say  the  object 
is  lead  without  drawing  upon  the  knowledge  already  in  my 
mind  and  supplementing  the  given  sensory  experience  by 
something  not  obviously  present?  Here  we  have  the  "un- 
conscious inference"  of  Helmholtz.  When  we  examine  our 
perceptions  carefully,  we  are  struck  with  the  poverty  of 
the  given  sensory  experiences  and  with  the  wealth  of  conscious 
contenT  read  into  them  through  the  process  of  apperception. 
Very  little  is  given  by  external  stimuli,  much  comes  out  of 
the  contents  of  past  experience.  If  the  word  ^v%»;  were 
shown  or  spoken  to  a  person  ignorant  of  the  Greek  language 
he  would  experience  the  sensory  visual  form  of  the  word, 
or  hear  the  sound,  but  form  or  sound  would  mean  nothing 
to  him.  But  if  he  ^  were  familiar  with  the  Greek  language 
he  would  understand  the  word  directly.  It  would  then 
have  meaning  for  him.  In  the  case  of  the  lead  paper-weight 
just  referred  to,  the  sensory  presentation  (color,  etc.)  means 
"lead"  for  me,  and  I  perceive  it  as  lead.  In  a  similar  way 
all  the  familiar  objects  about  me — books,  tables,  chairs,  etc.—- 


340  PSYCHOLOGY 

have  meanings  by  virtue  of  which  I  apprehend  them  directly. 
But  suppose  an  object  with  which  I  am  not  familiar — several 
small  shell-like  beads  strung  together — comes  to  my  notice. 
I  am  at  first  unable  to  apprehend  it.  I  stop  and  search  for 
its  meaning  and  then  it  dawns  upon  me  that  it  is  a  piece  of 
Indian  money,  or  wampum.  In  this  case  my  understanding 
of  the  object  is  indirect,  mediated  by  my  knowledge  of  early 
Colonial  times.  The  mental  process  by  which  I  find  its  mean- 
ing is  very  much  like  inference,  or  reflective  thought.  There 
Bare,  then,  two  ways  of  grasping  the  meaning  of  a  given  pres- 
entation— direct  and  indirect  understanding.  In  direct 
understanding  the  object_and  its  meaning  are  so  closely 
united  that  they  appear  as  one.  In  indirect  understanding 
the  object  and  its  meaning  are  sundered  until  they  are  brought 
together  by  thought.  In  one  case  we  apprehend  (perception) 
and  in  the  other  we  comprehend  (inference)  a  given  presenta- 
tion. The  difference  between  perception  and  inference  lies 
• ,  •  only  in  the  manner  in  which  the  given  presentation  is  supple- 
mented or  interpreted.  If  the  interpretation  is  immediate, 
J  "we  have  perception,  but  if  the  interpretation  is  delayed  ^,nd 

involves  reflection  we  have  inference. 

'-••/  Inference  and  Judgment.— Inference  always  ends  in  judg- 

ment, but  all  judgments  are  not  inferences.  How  shall  we 
determine  when  a  judgment  rests  upon  inference  and  when  it 
does  not?  If  a  given  object  is  understood  at  a  glance,  as  in 
the  judgment,  "This  is  paper,"  we  have  a  simple  perception, 
judgment,  or  mere  apprehension.  If  we  say,  "This  paper  is 
white,"  we  have  an  analytic  judgment.  In  this  latter  case 
both  subject  and  predicate  are  given  and  analyzed  out  of 
a  total  sensory  presentation.  But  if  we  say,  "This  paper  will 
burn,"  it  is  not  easy  to  determine  whether  we  are  dealing 
with  a  synthetic  judgment,  or  with  inference.  If  the  quality 
of  combustibility  is  supplied  by  a  specific  memory  act,  or 
if  through  familiarity  with  paper  and  its  attributes  the  thought 
of  combustibility  follows  the  consciousness  of  the  paper 
immediately  or  habitually  as  an  association,  the  mental 


REASONING  341 

process  is  a  synthetic  judgment.  But  if  the  quality  of  com- 
bustibility is  added  because  of  the  larger  thought,  "Air 
paper  will  burn,"  then  the  judgment  rests  upon  an  infer-  \ 
ence.  Since  the  conscious  ground  for  inference  may  be 
present  in  all  degrees  of  explicitness  —  from  the  case  where 
it  is  only  implicitly  present  to  those  cases  where  it  is  con- 
sciously formulated  and  expressed  —  it  is  evident  that  syn- 
thetic judgment  shades  off  gradually  into  inference. 

Inference  and  Concept.  —  In  the  judgment,  "That  paper 
will  burn,"  the  inference  consists  in  regarding  the  presented 
object,  "  that  paper,"  in  the  light  of  a  larger  body  of  knowledge 
about  it.  Now,  since  the  concept  "paper"  is  a  group,  or 
system  of  meanings  which  points  out  or  signifies  this  larger 
body  of  knowledge,  it  becomes  evident  that  inference  is  the 
act  ofmaking  explicit  the  meanings  stored  away  in  the  gpn- 
cept.  Inference,  then,  may  be^lpoked  upon  as  the^process  of 

^selecting  the  proper  meanings  and 


^ 

making  tKenTexplicit  in_Judgni£nt—  ^ajijmfoidinfi-pf  the_con- 
cept  in  the  interest  of  some  problem  present  in  the  mind, 
For  instance,  in  this  particular  case  I  might  be  seafcKiiig;  fol* 
material  to  kindle  a  camp-fire.  When,  therefore,  a  part  of 
this  particular  system  of  knowledge  is  presented  to  conscious- 
ness, the  part  not  presented  but  needed  in  the  solution  of 
the  problem  is  called  into  action.  Inference,  then,  makes 
actual  and  explicit  what  is  potentialanrl  implicit  in  t^g 
concepjt.  If  it  were  not  for  the  fact  that  knowledge  organizes 
itself  into  systems  in  which  one  part  sustains  relations  to  other 
parts,  and  in  which  the  system  as  a  whole  subsumes  all  its 
parts,  inference  would  be  impossible.  Psychologically,  of 
course,  the  whole  system  is  never  presented  at  any  one  mo- 
ment, but  its  parts  are  potential  in  the  concept  in  the  form  of 
meanings.  Inference  may  be  regarded  as  a  penetrating  insight 
into  or  a  searching  analysis  of  our  concepts  for  the  purpose 
of  revealing  the  solution  of  a  problem  before  the  mind. 

While  inference  involves  analysis,  it  also  involves  syn- 
thesis.     It  is  quite  as  truly  the  act  of  adding  new  meanings 


342  PSYCHOLOGY 

to  our  concepts.  For  instance,  my  individual  notion  "that 
paper"  may  not  contain  the  meaning  "combustibility." 
It  may  not  occur  to  me  that  that  piece  of  paper  will  burn 
until  I  have  analyzed  this  characteristic  out  of  my  general 
knowledge  and  added  it  by  means  of  the  inference  to  my 
individual  concept  "that  paper."  Inference  is  therefore 
synthetic  as  well  as  analytic.  We  shall  have  more  to  say 
about  this  point  when  we  consider  the  deductive  and  induc- 
tive methods  of  thought. 

The  Nature  of  Reflective  Thought,  or  Reasoning. — A  mere 
succession  of  mental  states  does  not  constitute  thinking  in  the 
ighest  sense.  Thinking  is  not  merely  a  series  of  conscious 
states,  but  a  sequence  of  conscious  states  in  which  each 
jfctate  determines  the  next  as  its  consequence.  We  recognize 
this  when  we  speak  of  the  "thread  of  thought."  Thinking 
is  properly  limited  to  the  acceptance  of  ideas  because  they 
rest  upon  evidence  or  knowledge  which  transcends  imme- 
diate presentation. 

Reflective  thought  involves  the  awareness  of  the  grounds 
for  our  conclusions  at  the  tune  they  are  made.  Much  of 
our  so-called  thinking,  however,  does  not  involve  the  grounds 
for  belief.  Oftentimes  we  take  things  for  granted,  either 
because  we  accept  the  word  of  others,  or  because  of  tradition, 
or  because  we  are  influenced  by  our  own  personal  advantage 
or  emotional  interests.  In  such  cases  there  is  no  examination 
of  the  real  grounds  for  our  conclusions.  Superstitions  and 
prejudices  arise  in  this  way.  Belief  in  protective  tariff,  or 
free  trade,  in  the  fatal  outcome  of  thirteen  at  table,  in  our  own 
possessions  as  the  best  in  the  neighborhood,  and  in  our  own 
actions  as  right,  etc.,  etc.,  too  often  arises  not  because  we 
consider  these  beliefs  in  the  light  of  the  evidence  that  supports 
them,  but  because  of  the  factors  just  mentioned.  Locke 
says  that  the  lack  of  reflective  thought  can  be  traced  to  such 
sources  as  (i)  the  tendency  to  depend  upon  the  thought  of 
others  and  thereby  avoiding  the  pains  and  troubles  of  think- 
ing for  ourselves,  (2)  the  tendency  to  put  passion  in  the 


REASONING 


343 


place  of  reason,  and  (3)  the  lack  of  knowledge  of  facts  due  to 
circumscribed  or  limited  experience.  Now,  while  psychology 
is  not  concerned  witrithe  question  whether  a  given  thinking  \ 
process  is  correctj>r"iricorrect,  it  is  interested  in  determining  \ 
what  mental  elements" ale  fuemd  in  both  good  and  bad  think- 
ing. It  may,  therefore,  point  out  the  difference  between  the 
thinking  process  which  utilizes  the  grounds  or  warrant  for 
its  conclusion  and  the  thinking  process  which  does  not.  It 
is  this  difference  which  distinguishes  reflective  thinking 
from  mere  association,  or  succession  of  ideas.  The  man  who 
reads  the  barometer  and  predicts  rain  may,  or  may  not,  be 
thinking  in  a  reflective  way.  If  he  understands  the  relation 
between  a  low  barometric  reading  and  low  atmospheric  pres- 
sure, and  if  he  understands  why  low  atmospheric  pressure 
is  favorable  to  storm  formation,  then  his  conclusion  may 
rest  upon  and  come  out  of  this  understanding.  In  thi 
case,  he  is  exercising  reflective  thought,  or  reason.  But  if 
the  relation  between  low  barometer  and  storm  formation  is 
no  part  of  his  thought — if  he  thinks  or  predicts  rain  simply  ^ 
because  he  merely  associates  low  barometer  with  rain,  then 
his  thinking  is  of  the  unreflective  type. 

The  Steps  in  Thinking. — Dewey,  in  his  excellent  little 
book,  "How  We  Think,"1  analyzes  a  complete  act  of  thought 
into  five  distinct  steps:  (i)  the  problem,  or  felt  difficulty; 
(2)  the  location  and  definition  of  the  problem;  (3)  suggestions 
of  possible  solutions;  (4)  the  development  of  the  implications 
of  the  suggestions;  (5)  further  observation  and  experiment 
leading  to  acceptance  or  rejection  of  the  suggestions.  This  is 
a  formal  and  logical  outline  of  the  phases  of  a  more  or  less 
protracted  series  of  thoughts  centering  about  some  problem. 
We  may,  however,  profitably  examine  it  for  the  light  it  throws 
upon  the  psychology  of  thinking.  The  first  step  refers  to 
the  fact  that  reflective  thought  originates  in  the  presentation 
to  consciousness  of  some  perplexity  or  difficulty.  If  every- 
thing presented  to  us  could  be  understood  at  a  glance  there  ) 

1  Chapter  6.  *£ 


344  PSYCHOLOGY 

would  be  no  occasion  for  thought.  The  second  step  con- 
sists in  comprehending  the  nature  of  the  difficulty  or  problem. 
In  most  cases  the  presentation  of  the  problem  and  its  loca- 
tion and  definition  come  to  consciousness  at  the  same  time. 
Steps  one  and  two  are  often  not  separable.  The  third  step 
-^conGJot-j  in  thr  nrousal  of  suggestions  for  the  solution  of  the 
.  .^problem.  This  step  is  inference  asjwejiave  discussed  it. 
p"\  The  suggestion  is  something  not  presented  in  the  given  situa- 
\1  tion,  but  supplied  out  of  our  general  knowledge.  The  fourth 
step  is  finding  out  what  implications  follow  the  suggestion, 
and  the  fifth  step  is  determining  through  observation  or  experi- 
ment whether  the  implications  tally  with  the  facts  as  found  in 
further  observation  of  the  given  situation.  This  last  step  is 
the  verification  of  the  suggested  solution.  XIntil  this  takes 
ace  the  rrmr^ginn  ir  TnEpntWiral  If  the  implications 
are  found  to  be  true  then  we  accept  the  suggested  solution 
as  the  true  one.  We  may  use  Professor  Dewey's  illustration  of 
the  steps  of  thinking  in  a  particular  case.1  Suppose  that  a 
man  on  entering  his  rooms  finds  the  contents  of  his  drawers 
emptied  upon  the  floor  and  everything  in  confusion.  At 
first  he  is  perplexed.  Here  is  something  to  be  explained. 
Steps  (i)  and  (2) — the  problem  and  its  definition — appear 
together,  because  he  understands  the  nature  of  the  problem 
at  once.  The  next  step  (3)  is  the  arousal  of  suggestions. 
Burglary  occurs  to  him  as  an  explanation.  Other  suggestions 
might  also  come  to  mind — pranks  of  children — some  friend 
may  have  been  playing  a  joke.  If  burglars  have  been  in 
his  rooms  then  he  will  find  his  jewels  and  money  gone  and  the 
locks  forced.  This  is  step  (4)  or  the  development  of  the  im- 
plications of  the  suggestion.  Step  (5)  is  further  observation 
to  find  out  if  the  implications  are  true.  Carrying  out  this 
step,  he  finds  that  one  of  the  windows  has  been  broken  open 
and  that  all  his  money  is  gone.  This  closes  the  matter  and 
he  accepts  the  hypothesis  as  a  reasonable  one. 

Now,  it  is  plain  that  the  central  psychological  process 
1  See  Dewey,  "How  We  Think,"  chap.  7. 


REASONING  345 

among  these  various  steps  is  the  inference.  It  is  found  both 
in  the  arousal  of  suggested  solutions  of  the  problem,  and  in 
the  development  of  the  implications  of  the  suggestion.  When 
the  man  in  the  illustration  passes  in  thought  from  the  presented 
situation  (disordered  room)  to  something  not  presented 
(burglars)  he  is  making  use  of  inference.  Likewise  his  mental 
process  is  inferential  when  he  concludes  that  if  burglars  have 
entered  his  rooms  he  will  find  his  money  gone  and  the  doors 
or  windows  forced.  In  the  one  case  the  movement  of  thought 
is  from  presented  particular  things  to  some  general  principle 
of  explanation,  while  in  the  other,  the  movement  is  from  the 
general  principle  back  to  particulars.  The  first  movement 
of  thought  is  inductive  and  the  second  is  deductive. 

Kinds  of  Reasoning. — Inference,  then,  may  be  of  two 
kinds:  induction,  or  deduction.  It  is  deductive  when  we 
pass  from  a  general  principle,  to  some  particular  case  and 
believe  in  the  particular  because  of  the  general  principle. 
If  we  infer  that  a  particular  piece  of  lead  is  heavy  because  of 
the  general  law  that  all  lead  is  heavy  the  inference  is  deduc- 
tive. On  the  other  hand,  inference,  is  inductive  when  we 
pass  from  particulars  to  a  general  principle,  or  law,  and  believe 
in  the  general  law  because  of  the  particulars.  If,  after  observ- 
ing that  every  particular  piece  of  lead  that  we  have  come  in 
contact  with  is  heavy,  we  infer  that  all  lead  is  heavy,  the  in- 
ference is  inductive. 

It  is  commonly  said  (i)  that  in  deduction  thought 
goes  from  the  general,  or  universal,  to  the  particular,  while 
hi  induction  thought  goes  from  the  particular  to  the  general; 
and  (2)  that  induction  precedes  deduction.  While  these 
statements  may  be  true  from  the  point  of  view  of  logic  we 
shall,  in  our  psychological  treatment,  have  reason  to  modify 
them  somewhat.  In  actual  thinking  there  is  no  such  thjng 
as  purely  inHiirtive  or  cfedurtiye  thought.  Any  specific  case 
of  thinking  involves  both  the  inductive  and  deductive  proc- 
esses. In  some  cases  the  emphasis  of  thought  is  on  the 
deductive  side  while  in  other  cases  it  is  on  the  inductive.  It 


346  PSYCHOLOGY 

is  evident  that  deduction  is  the  application  of  old  knowledge 
or  habits  of  thinking  to  new  situations,  while,  indurfionjs  the 
formation  of  principles,  or  habits  of  thiflkinff.     But  induction 
cannot  take  place  without  the  deductive  use  of  old  knowledge. 
In  so  far  as  it  is  necessary  to  identify  each  particular  case  in 
the  induction  which  yields  the  general  principle  "All  lead  is 
heavy,"  the  process  is  deductive.     Without  the  application 
of  old  knowledge  we  could  not  know  that  the  different  pres- 
entations or  individual  cases  belong  to  the  class  under  observa- 
tion.    In  order  to  be  sure  that  the  induction  will  be  valid 
each  new  instance  must  be  tested  by  old  principles  of  knowl- 
i  edge.     The    inductive    movement,    therefore,    is    constantly 
I  under  the  guidance  of  the  deductive  process.     Moreover,  in 
I  practical    thinking    induction    seeks    the    general    principle 
through  particular  facts  not  merely  for  the  purpose  of  finding 
I  the  general  principle  but  for.  the  purpose  of  explaining  or 
interpreting  other  particular  facts.     Induction,  then,  is  not 
l|  so  much  a  movement  of  thought  from  the  particular  to  the 
\  general  as  it  is  a  movement  from  particular  facts  to  particular 
/|  facts  through  the  general  principle  which  is  used_rmt  a.s  a% 
\\  endjnitseltbut_as  a  basis_or  ground  ot  explanation.     Neither 
»*  is  it  absolutely  trueTthat  induction  precedes  deduction.     They 
both  take  place  at  the  same  time.     We  do  not  first  collect 
a  lot  of  facts  and  then  generalize  them.     But  from  the  very 
first  the  facts  are  collected  under  deductive  control,  i.  e., 
each  new  fact  becomes  a  basis  of  interpreting  succeeding  facts. 
Deduction  just  as  truly  involves  the  inductive  movement 
of  thought.     When  we  apply  a  general  principle  to  an  indi- 
vidual case  and  infer  that  a  specific  consequence  will  follow 
because  of  the  general  principle,  the  inferred  fact  then  be- 
comes a  new  instance  for  the  support  of  the  general  principle. 
In  so  far  as  we  think  of  it  as  new  evidence  for  the  validity 
of  the  general  principle,  we  are  generalizing  in  an  inductive 
way.     In  practical  thinking  general  principles  are  rarely  so 
complete  that  they  are  not  fortified  or  modified  by  the  new 
specific  instances  or  individuals  brought  under  them.     When 


REASONING  347 

an  individual  case  modifies  or  changes  a  law  the  thought 
movement  is  inductive.  Concerning  the  time-worn  state- 
ment that  in  deduction  the  movement  of  thought  is  from  thel 
general  to  the  particular,  observation  of  real  cases  of  think-j 
ing  outside  of  logic  books  will  show  that  here,  too,  the  move-i 
ment  is  from  particular  fact  to  particular  fact.  Practical 
thinking  never  starts  with  a  general  principle,  but  rather  with 
individual  and  specific  facts.  In  deduction  it  is  always  some 


particular  individual  presentation  that  _r^]1s  for  intferprqfa- 
tiori.  If  we  infer  that  "that  paper  will  burn,"  or  that  Soc- 
rates is  mortal,  the  thinking  is  started  by  the  particular 
piece  of  paper  or  the  particular  Socrates,  and  proceeds  to  the 
particular  idea  combustibility  or  mortality.  In  deduction 
it  is  the  individuaLlhat  is  problematic  and  is  given  a  par- 
ticular interpretation  by  virtue  of  the  general  principle.  J^n 
induction  some  particular  instance  makes  the  general  principle 
problematic  and  either  modifies  if  nr  supports  it.  In  all  cases 
practical  thought  begins  and  ends  in  particular  facts. 

There  is  another  form  of  inference  which  is  usually  con- 
sidered inductive  in  method  although  it  is  based  upon  a  sin- 
gle case.  I  refer  to  reasoning  by  analogy.  Inference  here  is 
based  upon  the  similarity  between  individual  cases.  If,  for 
instance,  I  infer  that  salt  is  sweet  because  of  its  similarity  to 
sugar  I  am  reasoning  by  analogy.  The_argument  jor  mental 
telepathy  based  jupon  wireless  jelegraphy  is_  a  case  of  reason- 
ing_byanalogy.  There  is  a  psychological  tendency  to  think 
thatif  "a""  manifests  the  characteristic  "c,"  then  "b" 
which  resembles  "a,"  will  also  have  the  characteristic  "c." 
The  degree  of  belief  aroused  will  vary  with  the  closeness  of 
the  similarity  between  the  cases.  Logic  does  not  consider 
inferanrf!  by  analogy  valid,  and  WP  mn^f  a.Httiit  that  if  is  foe 
source  of  many  errors  in  thinkjng.  It  is,  however,  very  widely 
used  in  our  every-day  thinking. 

Logicians  have  claimed  that  deductive  reasoning  can 
not  make  any  advance  in  thinking  or  give  any  new  truth,  for 
the  reason  that  the  conclusion  is  already  contained  in  the 


348  PSYCHOLOGY 

general  principle.     If,  for  instance,  we  know  that  "all  lead  is 

heavy,"  we  certainly  must  know  that  any  particular  instance 

of  lead  is  heavy,  so  that  the  deductive  conclusion  in  such 

cases  is  not  a  new  truth.     We  hold,  however,  that  in  many 

'cases    what    is   contained   in  a  general  principle  may  not 

{have  been  applied  by  us  to  all  specific  cases  which  can  be 

'subsumed  under  it.     When  we  make  this  application  the 

|  deductive  conclusion  is  a  real  gain  and  is,  so  far  as  we  are 

concerned,  a  new  truth. 

On  the  other  hand,  inductive  inference  has  been  criticised 
on  the  ground  that  it  cannot  properly  go  beyond  the  par- 
ticular facts  which  have  actually  been  examined  and  there- 
fore does  not  add  anything  to  our  knowledge.  For  this 
reason  the  validity  of  inductive  generalizations  has  been 
questioned.  By  what  warrant  or  right  can  we  assert  the 
general  law  that  "all  lead  is  heavy"?  We  are  unable  to 
examine  all  the  cases,  so  that  the  method  of  enumeration  can 
never  be  completed.  Therefore,  to  pass  from  the  cases 
examined  to  the  general  law  is  the  so-called  "inductive  leap." 
1 1  The  difficulty  here  comes  from  the  attempt  to  consider  induc- 
Jtion  as  a  method  of  thought  separate  and  apart  from  deduc- 
•tion.  The  warrant  for  the  so-called  inductive  leap  is  essen- 
tially a  deductive  one.  Isolated  facts  are  of  no  value,  they 
cannot  be  used  without  some  reference  back  to  accumulated 
experience.  No  particular  experience  becomes  effective  ex- 
cept as  it  is  incorporated  into  old  habits  or  types  of  thinking. 
The  power  of  induction  to  establish  belief  does  not  come  from 
the  particulars  as  particulars,  but  because  they  express  pre- 
viously established  principles  or  represent  typical  conditions 
of  the  world  as  we  know  it.  To  be  more  explicit,  if  we  find 
a  certain  characteristic  like  heaviness  always  present  in  a 
number  of  cases  of  lead,  we  are  predisposed  by  past  experi- 
ence to  expect  that  this  characteristic  will  be  found  hi  all 
pieces  of  lead.  We  have  grown  to  believe  in  the  general 
i\  principle  that  nature  is  uniform  and  law-abiding  in  her  mani- 
jj  festations.  We  have  faith  in  the  general  law  that  whatever 


REASONING 

happens  under  given  conditions  will  always  happen  under 
the  same  conditions.  So  strongly  is  this  principle  intrenched 
in  our  minds  that  we  are  willing  to  make  inductive  generaliza- 
tions upon  the  examination  of  a  single  case  provided  the 
case  is  a  typical  individual  of  its  class.  When  this  is  true, 
one  case  is  as  good  as  a  hundred.  The  warrant,  then,  for  in- 
ductive inference  is  found  in  a  general  principle  formulated  in 
the  mind  by  past  experiences. 

Reasoning  and  the  Syllogism. — The  logician  looks  upon 
inference  as  the  process  of  uniting  two  judgments  in  such 
a  way  that  a  third  judgment,  containing  a  new  truth,  arises 
as  a  conclusion.  This  series  of  judgments  is  the  syllogism: 

All  lead  is  heavy; 

This  paper-weight  is  lead, 

Therefore,  this  paper-weight  is  heavy. 

These  three  judgments  are  called  the  major  premise,  the  minor 
premise,  and  the  conclusion.  The  major  premise  asserts  a 
general  principle.  The  minor  premise  applies  the  general 
principle  to  a  particular  case  and  the  conclusion  states  the 
new  truth.  This  is  the  syllogism  of  deductive  logic.  In- 
ductive logic  has  no  one  special  form  of  inference,  although 
it  has  several  different  methods  through  which  inductive 
inference  works.  To  one  who  has  observed  what  really 
happens  when  he  is  reasoning,  it  is  evident  that  the  syllogism 
does  not  represent  the  manner  in  which  conclusions  are 
reached.  In  most  cases  of  actual  thinking  the  -only  thing 
that  is  clearly  formulated  in  consciousness  is  the  conclusion. 
The  minor  premise  is  rarely  if  ever  formulated  when  we  are 
making  inferences.  The  major  premise  may  sometimes 
come  formally  to  consciousness  when  there  is  some  doubt 
about  the  conclusion,  but  usually  the  first  and  only  thing  to 
appear  clearly  in  consciousness  is  the  conclusion.  We  do 
not,  therefore,  proceed  in  the  svllngist.ir  manner  if|  acjj.ua! 
thinking.  Both  the  syllogism  of  deductive  logic  and  the 
methods  of  inductive  logic  are  forms  of  proof  for  testing 


HL,    359^ 


PSYCHOLOGY 

trie  truth  or  falsity  of  conclusions  after  they  have  been  made. 

We  must,    therefore,   distinguish   between  inference   as   the 

actual  mental  process  which  gives   conclusions,   and  proof 

which  is  the  method  of  logic  for  testing  the  results  of  reason- 
jing.  Logic  deals  with  proof,  not  with  the  inner  mental 

process  of  making  inferences.  Logic  is,  therefore,  interested 
i  in  arranging  facts  into  ideal  systems  (logical  concepts  and 
(judgments),  in  showing  the  necessary  relationships  which 
\exist  between  these  systems,  and  in  giving  methods  of  com- 

jbining  them  (syllogism)  for  the  purpose  of  testing  the  validity 

of  our  conclusions. 

If  we  examine  the  reasoning  process  for  the  purpose  of 
'finding  out  how  conclusions  actually  arise,  we  shall  see,  as 

we  have  already  pointed  out,  that  they  arise  t.h rough ^tsug- 
^gestions,  both  in  the  deductive  and  inductive  processes.     The 
nf  ^ngge^tions  is  controlled  by  the  laws  of  association. 

Thus,  if  I  am  seeking  material  to  kindle  a  fire,  the  moment  my 

eyes  fall  upon  paper  the  next  thought  is:    "That's  it,  that 

paper  V/ill  burn."      The  rfmtpYt_nf  tVirmght  (pnrpncf  r>r  pfc n^ 

and  the  link  of  identitvii  between  the  idea  fire  and  the  idea 
paper,  determine 'the  inference.  The  guidance  of  the  reason- 
ing process  is  found  in  the  character  of  consciousness.  What 
suggestions  arise  in  a  given  situation  depends  upon  the  past 
xperiences,  range  of  information,  sagacity,  temperament, 
interests,  purposes,  and  recent  experiences  of  the  individual, 
together  with  the  context  in  which  the  problem  for  thought 
arises.  The  ability  to  pick  out  of  a  total  situation  the  vital 
and  important  characteristics  differentiates  the  mind  of  a 
Newton  or  a  Darwin  from  that  of  the  ordinary  man.  The^ 
law  of  association  by  similarity  is  most  Jmportant  in  reason- 
ing. _The  mind  which  easily  detects  identity  among  diver- 
sity, or  sees  delira|e  and  siir^le  relationships  of  similarity, 
manifests  very  clearly  the  real  mental  process  involved"  in 
inference.^  In  order  to  detect  identities  among  differences 
one  must  possess  what  James  calls  "sagacity  or  the  percep- 
tion of  the  essence  of  things,"  i.  e.,  the  power  to  resolve  total 


REASONING  351 

situations  into  their  essential  elements  and  " perceive" 
accurately  what  they  contain — the  power  to  discriminate  and 
properly  evaluate  the  elements  of  whatever  is  presented.  ^ — 

Imageless  Thought. — It  has  been  very  generally  assumed 
that  the  content,  or  actual  mind  stuff  of  our  thinking  proc- 
esses, is  derived  from  sensory  experiences — that  the  original 
material  of  thinking  comes  from  the  various  senses.  The 
contents  of  a  thought-process  would  then  be  either  a  sensa- 
tion, or  a  group  of  sensations  (perception),  or  images  or  mem- 
ories of  these  sensations  and  perceptions.  Even  the  rela- 
tional elements  between  the  terms  of  thought  are  considered  ±3*^ 
by  some  psychologists  to  have  a  sensory  content.  Titchengjl  I1 
believes  that  the  content  of  relational  consciousness  is  given 
by  motor  tendencies,  or  attitudes,  whose  representations  ir| 
consciousness  are  faint  kinaesthetic  sensations  or  images. 
Miss  Washburn,  writing  on  this  same  point,  savs  that  tfce 
relatkmal  elements  of  ™nsn'rmsr>fss  are  the  remnants  of  rp,- 
mote  ancestral  motor  attitudes-  The  relational  experience  I. 
represented  by  the  word  "but,"  for  instance,  is  now  the  ves-  1} 
tige  of  the  kinaesthetic  sensations  originally  set  up  in  primi-ji 
tive  organisms  by  simultaneous  stimuli  calling  for  two  incom- \\ 
patible  reactions  at  the  same  time.  The  experience,  she  says, 
was  that  of  a  certain  suspended,  baffled  motor  attitude. 
In  short,  the  theory  of  sensationalism  holds  that  all  con- 
sciousness, even  the  elements  of  reflective  thinking,  can  be 
traced  back  to  sensations.  Even  those  who  do  not  go  the 
whole  length  of  sensationalism,  i.  e.,  those  who  are  not  willing 
to  admit  that  relational  elements  and  meaning  are  reducible 
to  sensations,  have  all  along  assumed  that  every  thinking 
process  does  contain  sensory  and  imaginal  content,  and 
that  thought  cannot  take  place  without  some  substantive 
content  of  a  sensory  character  either  directly  experienced  or 
imaged.  The  "no  thought  without  images"  theory  has  been 
recently  and  vigorously  attacked  by  a  group  of  American  and 
German  psychologists  who  believe  that  they  have  discovered 
"imageless  thought."  They  contend  that  thinking  may  go 


352  PSYCHOLOGY 

on  without  any  imaginal,  or  sensory,  content  whatever.  Ac- 
cording to  them  thinking  may  be  carried  on,  and  frequently 
is  in  its  highest  forms,  in  terms  of  a  "pure  thought  element." 
This  non-imaginal  thought  element  can  be  detected  by  in- 
trospection, if  we  accept  the  statements  of  the  imageless- 
thought  psychologists.  They  claim  that,  when  we  think, 
there  are  elements  of  thought  present  in  the  field  of  conscious- 
ness which  are  neither  sensory  nor  affective  in  character,  but 
which  nevertheless  constitute  a  content  of  consciousness. 
They  claim  further  that  this  content  may  exist  independently 
of  sensations  or  images.  Thus  Woodworth  says:1  "Accord- 
ing to  my  experience,  the  more  effective  the  thinking  process 
is  at  any  moment,  the  more  likely  is  imageless  thought  to  be 
detected,  provided  only  one  introspects,  which  is  not  apt  to 
be  the  case  at  such  moments." 

As  an  illustration  of  imageless  thought  we  may  quote  the 
following  from  Woodworth's  notes:2  "While  reading  I  heard 
some  one  playing  on  the  piano  a  piece  which  I  felt  at  once  to 
be  familiar,  but  which  I  did  not  at  first  identify.  My  first 
>  ^attempt  at  identification  was  felt  to  be  wrong,  and  imme- 
<  diately  afterward  I  identified  it  properly  and  with  confidence. 
In  doing  so  I  thought  of  the  first  part  of  the  piece  (it  was 
Chopin's  'Funeral  March,'  and  the  part  being  played  when 
it  caught  my  attention  was  the  trio).  Resting  satisfied  with 
my  identification,  I  was  about  to  turn  to  other  things,  when 
it  occurred  to  me  to  ask  whether,  in  identifying  the  piece,  I 
had  had  its  name  present  in  the  form  of  verbal  imagery,  and 
I  found  that  I  certainly  had  not;  in  fact,  it  required  a  moment's 
further  thought  to  recall  the  sound  of  the  composer's  name 
and  the  name  of  the  piece.  Nor,  in  locating  the  trio  as  a  trio 
and  thinking  of  the  character  of  the  march  proper,  did  I 
have  an  auditory  image  of  the  march.  I  regard  the  example 
as  a  good  one,  since  the  thought  was  perfectly  overt,  conscious, 


1  Journal  of  Philosophy,  Psychology,  and  Scientific  Method,  III,  1906,  p.  703. 
8  Ibid.,  p.  705. 


REASONING  353 

and  definite,  though  it  not  only  began  but  was  completed 
without  any  image." 

It  is  claimed  that  the  pure-thought  element  shows  itself 
plainly  in  cases  where  we  are  given  a  definite  mental  task  to 
do,  such  as  that  required  in  a  laboratory  experiment.  At 
each  command  to  make  a  definite  reaction  we  know  exactly 
what  we  are  to  do  and  yet  there  is  no  imagery  of  any  kind 
whatsoever.  The  thought  of  the  act,  or  the  response,  or 
whatever  the  task  may  be,  is  perfectly  definite,  and  yet  it 
is  imageless.  It  is  also  claimed  that  meaning  may  be  present 
in  the  mind  alone  without  any  image  or  sensory  experience. 
We  have  described  a  concept  as  an  image  of  some  kind,  plus 
meaning.  Now,  the  advocates  of  imageless  thought  contend 
that  the  meaning  may  exist  in  consciousness  without  the  image. 
One  may,  they  say,  think  of  a  thing  purely  in  terms  of  its 
meaning  without  any  visual,  auditory,  or  other  image  of  the 
thing. 

The  imageless  "thought  content,  or  element"  has  received 
various  names  in  the  different  attempts  to  describe  it.  Some 
of  the  descriptive  terms  are:  " conscious  attitude,"  "determin- 
ing tendency,"  "conscious  predisposition  toward,"  "problem" 
or  "Aufgabe"  "mental  set." 

The  imageless-thought  advocates  have  not  succeeded  in 
winning  all  psychologists  to  their  point  of  view.  Angell1  and 
Titchener2  have  published  very  vigorous  attacks  upon  the 
theory.  It  is  generally  contended  that  the  "conscious  atti- 
tudes" or  "determining  tendencies,"  constituting,  according 
to  the  imageless-thought  psychologists,  the  whole  of  thought 
at  times;  are  merely  conscious  processes  of  perception  or 
thinking  which  have  become  so  habitual  and  automatic  that 
the  imagery  involved  has  dropped  into  the  background  of 
consciousness  and  is,  therefore,  difficult  to  detect.  In  other 

1  Psychological  Review,  vol.  18,  1911,  p.  295. 

3  "  Experimental  Psychology  of  the  Thought  Processes,"  1909.  See  also  an 
article  by  Book,  "On  the  Genesis  and  Development  of  Conscious  Attitudes," 
Psychological  Review,  vol.  17,  1910,  p.  381. 


354  PSYCHOLOGY 

words,  cases  of  so-called  imageless  thought  are  cases  where 
consciousness  is  shading  off  into  the  automatic  and  subcon- 
scious tendencies  and  reflex  responses,  where  there  is  not  only 
no  imaginal  content,  but  no  conscious  content  distinct  enough 
for  introspection. 

Roughly  speaking,  there  are  at  the  present  time  three 
groups  of  psychologists  distinguished  by  their  attitudes  to- 
ward imageless  thought.  First,  there  are  the  sensationalists 
who  believe  that  all  thought  processes  are  carried  on  in  terms 
of  sensations,  or  images,  or  both.  They  believe  that  meaning 
and  relational  consciousness  are  represented  by  sensory  con- 
tent of  some  kind.  Second,  there  are  those  who  accept 
the  "directive  tendencies"  and  "conscious  attitudes"  as 
phases  or  even  contents  of  consciousness,  but  they  believe 
that  they  are  always  attached  to  sensory,  or  imaginal  fac- 
tors and  do  not  exist  alone  in  consciousness.  Third,  there  is 
a  smaller  group  of  psychologists  who  believe  in  the  existence 
of  a  "pure  thought  content,"  independent  of  any  sensory  or 
imaginal  content. 

The  Neural  Basis  of  Reason.— We  are  not  yet  in  posses- 
sion of  sufficient  anatomical  and  physiological  knowledge  of 
the  brain  to  be  able  to  point  out  any  specific  cortical  areas 
as  thought  centres.  There  are  in  the  cerebrum  very  consider- 
able areas  which  are  not  involved  so  far  as  we  know  in  the 
reception  of  sense-impressions,  or  in  the  sending  out  of  motor 
impulses.  Two  large  areas  in  each  hemisphere  of  the  brain, 
one  in  the  frontal  region  and  one  in  the  occipi  to-parietal 
region,  commonly  known  as  the  associational  areas,  or  Flech- 
sig  centres,  have  been  thought  to  be  involved  in  the  higher 
thought  processes.  The  frontal  associational  area  especially 
has  been  considered  as  the  higher  centre  or  thought  centre. 
This  region  is  more  highly  developed  in  man  than  in  any  other 
animal,  which  fact  has  led  to  the  belief  that  the  frontal  con- 
volutions are  the  thinking  areas.  This  is  probably  a  good 
guess,  although  it  is  too  general  in  character  to  be  of  any 
value.  Without  doubt,  these  associatignal  areas  contain. 


REASONING 


355 


neurones  which  mediate  between  the  different  sensory  areas, 
and  between  the  sensory  areas  and  the  motor  areas,  and  so 
form  centres  of  interconnection  in  the  cortex.  But  just  what 
particular  brain  centres  are  active  in  moments  of  ratiocination 
we  do  not  know.  It  is  very  probable  that  the  thinking 
process  makes  use  of  very  wide-spread  regions  of  the  cortex, 
even  including  the  sensory  areas. 

In  cases  where  thought  is  not  required  to  respond  to  a 
given  presentation,  reactions  take  place  immediately  and  the 
nervous  pathway  from  stimulus  to  response  may  be  con- 
ceived as  relatively  simple  and  direct.  But  in  other  cases 
where  thought  is  needed  to  bring  the  light  of  past  experiences 
upon  the  present  situation  so  that  an  intelligent  response 
may  be  made,  the  impulses  started  by  the  stimulus  may  be 
conceived  as  shunted,  or  drained  off,  into  larger  areas  than 
those  involved  in  direct  response.  These  larger  areas  may 
be  thought  of  as  higher  centres  in  the  sense  that  their  activi- 
ties correspond  to  larger  and  more  highly  systematized  bodies 
of  knowledge,  meanings,  and  relationships,  gained  through 
past  experience.  When  we  realize  that  reasoning  is  not  a 
separate  kind  of  consciousness,  or  the  immediate  awareness 
of  a  given  situation,  but  rather  is  the  present  consciousness 
augmented  by  the  significance  or  essence  of  past  experi- 
ences, then  we  shall  cease  to  look  for  separate  brain  centres 
for  thinking.  On  the  other  hand,  we  should  expect  the  neural 
counterpart  of  reasoning  to  be  a  larger  brain  action,  involving 
not  onlyjjie  limited  neural  action  corresponding  to  the  p/es- 
ent-moment~presentation,  but  also  the  centres  correspond- 
ing to  past  perceptions,  memories,  and  images.  As  larger 
arid  larger  units  of  experience  are  awakened  and  incorporated 
into  the  present-moment  consciousness,  ever-widening  waves 
of  neural  excitation  must  sweep  over  the  cortex  as  the  neural 
counterpart  of  thought.  We  must  not  forget,  however,  that 
such  a  conception  of  the  matter  is  merely  a  conjecture  with 
a  very  meagre  body  of  fact  to  support  it. 


CHAPTER  XVI 
AFFECTION  AND   FEELING 

So  far  we  have  been  engaged  in  the  task  of  analyzing  and 
describing  the  mental  states  which  give  us  our  knowledge  of 
the  outer  world  of  objects  and  relations.  Sensations,  per- 
ceptions, memories,  judgments,  concepts,  and  reasoning  proc- 
esses— all  these  forms  of  cognitive  consciousness  may  be 
said  to  have  an  objective;  \efergnce,  in  that  they  refer  to 
things  and  relations  in  the  outer  world.  We  have  now  to 
examine  those  forms  of  consciousness  v  which  have  subjective 
reference.  We  not  only  kn<^w  objects  and  their  relations  but 
at  the  same  time.. we, are  subjectively  affected  by  them.  The 
mental  states  containing  "r-pffftin — qtt^idrs  flroused  in  us 
by_fhf  nhjprts  nf  niir  k^^^^gp  a^  raiipd_//Wt»7.g.c.  Thus  a 
sensory  experience  may  be  pleasing  or  displeasing;  we  may 
like  or  dislike  a  particular  person;  feel  joy  or  sorrow  in  the 
contemplation  of  certain  facts;  experience  annoyance  or  anger 
in  the  action  of  a  friend,  etc.  In  its  broadest  psychological . 
meaning,  feeling  is  the  term  which  denotes  all  those  states  of ; 
consciousness  which  are  characterized  predominantly  by  our  \ 
affective  attitudes. 

Affection. — Feelings  are  complex  conscious  states  consist- 
ing in  sensory  or  ideational  elements  and  the  purely  affec- 
tive consciousness  which  these  cognitive  or  ideational  experi- 
ences arouse.  When  the  affective  consciousness  predominates, 
the  total  conscious  experience  is  called  a  feeling.  The 
characteristic  factor  in  feeling  is  affection.  Affection  is  a 
unique  and  elementary  content  of  consciousness  always  accom- 
panying some  cognitive  process  and  never  existing  alone. 
Although  affection  is  aroused  by  and  accompanies  cognition, 
it  is  easily  distinguishable  from  the  cognitive  elements.  Af- 

356 


AFFECTION  AND   FEELING  357 

fection  manifests  itself  in  two  qualities  which  stand  in  direct 
opposition  to  each  other.  A  sensation,  perception,  memory, 
or  other  cognitive  state  may  be  (i)  agreeable  or  (2)  disagree- 
able  when  we  experience  it;  i.  e.,  we  are  agreeably  or  dis- 
agreeably affected  by  it.  Agreeableness  and  disagreeableness 
are  the  two  elementary  forms  of  affection.  Pleasantness 
and  unpleasantness  are  terms  also  used  to  designate  these 
two  forms  of  affection. 

Some  cognitive  processes  are  pleasantly  and  some  are 
unpleasantly  toned,  while  some  appear  to  be  nejiksftUn  affec- 
tive tone.  With  a  medium  intensity  of  stimulation  the 
taste  of  sugar  is  pleasant,  the  taste  of  quinine  is  unpleasant, 
while  certain  other  tastes  are  indifferent.  Memories  and 
ideas,  judgments  and  reasons,  in  short,  all  forms  of  cogni- 
tive process  may  be  pleasantly  or  unpleasantly  toned.  Some 
psychologists  have  been  willing  to  stand  for  the  statement 
that  every  cognitive  process  is  accompanied  by  affection  in 
some  degree  of  intensity — that  in  the  case  of  the  apparently 
indifferent  cognitive  experiences  the  affection  is  so  low  in 
intensity  that  it  is  below  the  threshold  of  consciousness  and 
so  does  not  reveal  itself  to  introspection.  If,  however,  we 
credit  the  report  of  introspective  observation,  we  are  forced 
to  admit  that  many  cognitive  experiences  are  neutral  so  far 
as  affection  is  concerned.  V\  *• 

The  Nature  of  Affection. — When  we  go  to  the  text-books  **  «/ 
for  an  answer  to  the  question,  What  is  the  real  nature  of  affec-  * 
tion?  we  get  a  variety  of  answers.  Some  psychologists  look 
upon  affection  simply  as  an  attribute  of  sensation,  just  as 
intensity  and  duration  are  attributes.  They  refer  to  affection 
as  the  " pleasure-pain  tone"  or  the  "affective  tone"  of  sensa- 
tion. They  think  of  affection  as  belonging  to  sensation,  never 
as  a  separate  affective  process.  The  objection  to  this  view 
lies  in  the  fact  that  affection  is  an  independent  variable  in  its 
relation  to  sensation.  It  may  or  it  may  not  accompany  a 
given  sensation,  and  some  sensations  are  without  affective 
tone  altogether.  Now,  an  attribute  does  not  usually  act  in 


358  PSYCHOLOGY 

this  way.  If  the  intensity  or  duration  of  a  sensation  should 
be  reduced  to  zero  the  sensation  itself  would  disappear. 
This  is  apparently  not  true  when  its  affective  tone  reduces  to 
zero.  Evidently  affection  is  something  more  than  an  attri- 
bute of  sensation.  Moreover,  affection  has  its  own  attributes 
— quality,  intensity,  and  duration. 

Other  psychologists  consider  affection  as  a  form  of  sen- 
sation akin  to  the  organic  sensations.  The  organic  sensations 
are  vague  and  undifferentiated,  poorly  localized,  and  have 
few,  if  any,  definite  qualities.  They  are,  therefore,  like  the 
affective  experiences.  Pleasantness  and  unpleasantness  may 
be,  it  is  thought,  organic  sensations  that'  are  -too  indefinite 
and  too  diffuse  for  clear  copm'tion.  .Thi(^"are  accordingly 
submerged  or  undeveloped  sensations.  Against  this  conten- 
tion we  may  mention  the  factr  that  affection  is  found  accom- 
panying all  kinds  of  sensations 'from  the  lowest  organic  sensa- 
tion to  the  most  highly  developed  visual  sensations.  This 
fact  indicates  that  affection  is  not  another  kind  of  sensa- 
tion but  a  unique  conscious  content  different  in  quality,  from 
the  sensory  content. 

r  Some  of  the  earlier  writers  took  an  intellectualistic  view 
of  affection.  Hegel,  for  instance,  held  that  affection  is  an 
obscure  kind  of  knowledge.  Wolff  thought  it  to  be  an  intui- 
tive knowledge  of  the  state  of  the  body.  In  this  latter  view 
the  intellectualistic  view  of  affection  changes  into  a  sensational 
view.  Another  and  more  definite  form  of  the  intellectualistic 
view  of  affection  is  that  which  considers  affection  as  the  rela- 
tion of  ideas,  or  sensations,  to  each  other.  In  aesthetic  experi- 
ences the  harmony  and  balance  of  parts — the  consonance  of 
tonal  sensations — are  pleasing,  while  lack  of  harmony  and 
balance  of  parts,  and  dissonance  of  tonal  sensations  are  dis- 
pleasing. The  experience  of  relationship  is  a  cognitive,  not 
an  affective  process.  The  affective  consciousness  is  something 
added  to  the  cognitions.  Although  affection  may  be  in  some 
cases  dependent  upon  the  relation  of  sensations  and  ideas 
to  each  other,  it  is  not  itself  a  relation.  Furthermore,  affeq- 


AFFECTION  AND   FEELING  359 

tion  is  not  always  dependent  upon  the  consciousness  of  re- 
lationship, it  may  also  be  connected  with  single  sensations 
and  ideas. 

We  have  so  far  rejected  the  views  (i)  that  affection  is  an 
attribute  of  sensation,  (2)  that  it  is  a  kind  of  sensation,  (3) 
that  it  is  an  obscure  kind  of  knowledge,  (4)  that  it  is  a  rela- 
tion.  What,  then,  is  its  real  nature?  In  the  opinion  of  the 
author  the  most  satisfactory  answer  is  thai  affficfiop  is__a, 
unique^  and  elementary- rncr^a]_(ContejfltT^iJFexeiiL-EnmL  but 

rn-nrdinq^p  wifrli^  ^n^'flyf;  fflT^Til       It  is  a  new  form  of  COn- 

sciousness  which,  while  dependent  upon  cognition,  neverthe- 
less plays  its  own  particular  part  in  our  conscious  life. 

Kinds  of  Affection. — We  have  already  stated  that  there 
are  two  elementary  and  opposite  forms  of  affection:  pleasant- 
ness and  unpleasantness.  All  psychologists  do  not  concur  in 
this  statement.  Wundt,  for  instance,  believes  that  there 
are  in  addition  to  pleasantness  and  unpleasantness  two  other 
pairs  of  opposing  affections:  excitement  and  calm,  and  strain 
and  relaxation.  This  view  is  known  as  the  "  tridimensional 
theory  of  affection."  He  holds  that  these  six  forms  of  affec- 
tion are  not  simple  or  elementary — that  each  has  a  large  num- 
ber of  different  qualities.  There  are  accordingly  many  kinds 
of  pleasantness,  unpleasantness,  etc.  Titchener  in  his  "Text- 
Book  of  Psychology,"  pp.  250-7,  attacks  Wundt's  theory 
very  vigorously.  In  the  first  place  he  points  out  that  while 
pleasantness  and  unpleasantness  are  in  every  essential  way 
opposites  in  nature,  neither  excitement  and  calm,  nor  strain 
and  relaxation  manifest  in  a  true  sense  any  such  relation. 
On  the  other  hand,  relaxation  is  the  minimum  degree  or  lack 
of  strain.  Likewise  calm  cannot  be  thought  of  as  the  real 
opposite  of  excitement,  but  rather  as  the  lack  of  excitement. 
Moreover,  excitement  and  calm,  or  tension  and  relaxation  may 
themselves  be  pleasantly  or  unpleasantly  toned.  How  can 
this  be  if  they  are  true  affections?  Wundt  holds  that  the 
character  of  affection  depends  upon  the  attributes  of  sensa- 
tion. Pleasantness  and  unpleasantness  depend  upon  the 


360  PSYCHOLOGY 

intensity  of  sensations.  Moderate  intensities  are  pleasing 
while  very  low  or  very  high  intensities  are  unpleasant.  Excite- 
ment and  calm  depend  upon  the  quality  of  sensations,  strain 
and  relaxation  depend  upon  the  temporal  attribute.  If 
sensations  are  too  slow  or  too  rapid  in  developing,  we  ex- 
perience strain,  but  if  their  time  aspect  is  normal,  we  experi- 
ence relaxation.  Titchener  thinks  this  view  inadequate,  in  that 
it  fails  to  take  account  of  the  spatial  attribute  of  sensation. 
What  kind  of  affection  corresponds  to  the  variations  in  our 
experiences  of  space?  If  the  other  attributes  of  quality, 
intensity,  and  duration  have  definite  affective  qualities  depend- 
ing upon  them,  why  is  extensity  lacking  in  this  respect? 

That  we  have  experiences  that  may  be  called  excitement 
and  calm,  strain  and  relaxation,  cannot  be  doubted.  Many 
psychologists,  however,  believe  that  these  experiences  are 
cognitive  and  not  affective  in  nature.  Strain  and  relaxation 
are  without  doubt  sensory  experiences  of  the  conditions 
of  the  muscular  system  (kinaesthetic  sensations).  Excite- 
ment and  calm  seem  to  consist  in  the  awareness  of  the  vivid- 
ness and  rate  of  change  in  our  mental  states  plus  certain 
kinaesthetic  sensations.  When  excited  our  respiration  and 
heart  actions  are  disturbed.  The  normal  rate  of  the  physi- 
ological processes  is  changed  and  the  general  activity  of  con- 
sciousness is  increased.  The  awareness  of  these  changes 
constitutes  the  major  part  of  the  experience.  It  cannot, 
therefore,  be  considered  as  affective  in  character.  Affection 
may,  of  course,  accompany  these  cognitive  processes,  but  the 
excitement  is  not  the  affection.  In  view  of  these  considera- 
tions, we  are  forced  to  abide  by  our  earlier  analysis  of  affec- 
tion into  pleasantness  and  unpleasantness  as  the  two  elemen- 
tary forms  of  affection. 

Attributes  of  Affection. — The  attributes  of  affection  are 
quality,  intensity,  and  duration.  We  have  found  that  the 
fundamental  qualities  of  affection  are  pleasantness  and  un- 
pleasantness. In  much  the  same  way  that  one  sensation 
differs  from  another  sensation  in  quality,  the  affection  pleas- 


AFFECTION  AND  FEELING  361 

antness  differs  from  the  affection  unpleasantness.  Whether 
there  is  only  one  quality  of  pleasantness  or  unpleasantness, 
or  whether  there  are  many  qualities,  is  a  question  that  has 
not  yet  been  settled  among  psychologists.  Affection  varies 
in  intensity.  An  experience  may  be  slightly  pleasant  or  very 
pleasant.  The  same  is  true  of  unpleasantness.  Affection 
also  varies  in  duration.  It  may  be  momentary  or  it  may 
continue  for  longer  periods. 

Adaptation.  —  Experiences  tend  to  lose  their  affective  char- 
acter when  long  continued.  Objects  and  events  that  are 
markedly  pleasant  or  unpleasant  at  first,  become  indifferent 
later.  A  pleasing  bit  of  color  or  a  beautiful  landscape  will 
in  time  become  indifferent  to  us  if  we  continue  to  experience 
it.  Likewise  a  disagreeable  odor  or  the  unpleasant  man- 
ners of  a  friend  will  under  the  same  conditions  fail  to  af- 
fect us. 

Affection  and  Sensation.  —  Since  affection  is  dependent 
upon  the  cognitive  processes,  we  shall  expect  to  find  it  related 
in  certain  ways  to  variations  in  these  processes.  First  of  all  Q) 
we  may  note  that  the  different  modes  of  sensations  do  not 
a^ouse_affection  in  the  same  degree.  The  more  highly  special- 
sensations  ffipffifl*  fo  have  less  affection  than  those  jhat  >, 


are  not  so  highly  specialized.  For  instance,  the  visual  sen-^p  .& 
sations  are  not  as  pleasing  or  displeasing  as  the  olfactory  or 
gustatory  sensations,  while  the  organic  sensations  have  the 
most  intense  affections.  Within  the  modes  themselves  affec- 
tion varies  with  the  quality,  intensity,  and  duration  of  sensa- 
tions. With  the  normal  intensity  and  duration  the  qualities 
of  some  sensations  are  inherently  agreeable  or  disagreeable. 
Thus  some  of  the  spectral  colors  are  more  agreeable  than 
others.  Tones  of  medium  pitch  are  more  pleasing  than  those 
of  very  high  or  very  low  pitch.  Sweet  is  agreeable  while 
bitter  is  disagreeable.  Why  some  qualities  of  sensations 
are  agreeable  and  some  disagreeable  is  a  question  to  which 
we  shall  return  later. 

Affection  varies  with  the  intensity  of  sensations.     Sen- 


362  PSYCHOLOGY 

sations  that  are  normally  agreeable  pass  over  into  disagreeable- 
ness  when  the  intensity  becomes  high.  A  tone  of  moderate 
intensity  may  be  pleasing,  but  if  the  tone  is  increased  in 
intensity  it  becomes  disagreeable.  With  a  continually  in- 
,  creasing  intensity  most  stimuli  finally  reach  a  point  where 
ifthe  pain  nerves  are  stimulated  and  the  sensation  of  pain  is 
'aroused.  The  pain  must  not,  however,  be  confused  with 
disagreeableness  of  the  original  sensation.  Sensations  that 
are  normally  disagreeable  become  increasingly  disagreeable 
when  their  intensities  are  increased.  All  sensations  of  very 
weak  intensities  appear  to  be  disagreeably  toned,  but  the 
affective  tone  may  be  due  to  the  difficulty  of  attending  to 
sensations  of  low  intensities. 

Sensations  that  are  normally  agreeable  may  become  dis- 
agreeable if  their  durations  are  either  too  brief  or  too  long. 
As  in  the  case  of  very  low  intensities  of  sensations,  very  short 
durations  may  owe  their  disagreeableness  to  the  processes 
of  attention  in  these  cases.  Agreeable  sensations  have  a 
definite  duration  during  which  their  agreeableness  is  at  its 
maximum.  When  adaptation  sets  in  agreeableness  passes 
into  the  region  of  neutrality  and  then  into  disagreeableness. 
Normally  disagreeable  sensations  appear  to  remain  disagree- 
able for  all  periods.  They  may,  however,  become  less  dis- 
agreeable through  adaptation. 

Pain  and  Affection. — The  fact  that  pain-sensations  are  in 
almost  all  cases  disagreeably  toned  has  contributed  to  the 
popular  belief  that  pain  is  disagreeableness  itself.  The  ex- 
pression "pleasure-pain  tone  of  sensation,"  has  been  very 
widely  used  even  in  psychology.  Pain,  however,  is  not  an 
affection,  but  a  sensation.  It  is  true  that  it  is  usually  accom- 
panied by  the  affection  of  disagreeablenes,  but  in  a  few  cases 
where  the  pain-sensation  possesses  a  very  low  degree  of 
intensity  it  may  be  neutral  or  even  agreeable.  Slight  stimu- 
lation of  certain  parts  of  the  body  by  an  electric  needle  give 
rise  to  fine  pain-sensations  that  are  of  an  agreeable  character. 
Charged  beverages  owe  their  agreeableness  partly  to  the 


AFFECTION  AMD   FEELING  363 

delicate  pain-sensations  aroused  mechanically  by  the  presence 
of  gas  in  the  beverages. 

Pain,  then,  offers  no  exception  among  sensations  in  its 
relationship  to  affection.  Popular  thought  does  not  easily 
accept  this  view,  for  the  reason  that  we  do  not  ordinarily 
consider  a  stimulus  painful  until  it  is  accompanied  by  dis- 
agreeableness.  Hence  the  confusion  in  ordinary  thought 
between  the  sensation  of  pain  and  the  affection  of  disagree- 
ableness. 

Affection  and  Perception.  —  Since  the  perception  of  an 
object  includes  the  presentation  of  several  sensory  qualities 
the  affective  tone  accnT^^nviny  the  perception  is  the  com- 
plex of  the  affections  belongrifff  tr> 


/ 


within  foe  perception.  Some  aspects  of  the  total  object  may 
be  pleasing  while  others  may  be  neutral  or  displeasing. 
Whether  the  resulting  affection  really  is  a  complex  made  up 
of  parts,  or  whether  it  is  a  unitary  and  unanalyzable  content 
accompanying  the  total  perception  process,  is  a  question  for 
future  determination.  Do  the  different  sensations  pool 
their  affections,  or  is  there  a  single  affection  depending  upon 
the  perception  ? 

Affection  and  the  Ideational  Processes.  —  Not  only  does 
affection  accompany  sensory  elements  and  perceptions,  it  also 
accompanies  ideational  processes.  Memory,  imagination, 
and  reasoning  processes  may  be  agreeable  or  disagreeable 
in  themselves.  But  since  these  ideational  processes  take  place 
in  an  organism  that  is  always  receiving  sensory  stimuli  of 
some  kind,  either  from  the  outer  world  or  from  the  organic 
processes  within,  it  is  sometimes  difficult  to  determine  how 
much  of  the  total  affection  is  due  to  the  ideational  process 
and  how  much  is  due  to  the  sensory  experiences.  We  cannot, 
however,  question  the  fact  that  the  higher  and  centrally  in-* 
itiated  processes  are  in  themselves  affectively  toned.  A 
memory  act  may  be  agreeable  or  disagreeable.  It  may  or 
it  may  not  have  the  same  quality  of  affection  that  belonged 
to  the  original  experience.  Oftentimes  experiences  that  are 


364  PSYCHOLOGY 

originally  pleasing  are,  when  remembered,  decidedly  unpleas- 
ant.    Whether  a  memory  act  is  pleasant  or  unpleasant  is 
|  determined  by  the  relation  of  the  recalled  experience  to  the 
ontents  of  consciousness  at  the  time.     If  it  stands  in  opposi- 
N  y\  ^on  to  our  Present  purposes,  desires,  and  ideas,  it  will  be 
•  unpleasantly  toned,  but  if  it  is  in  conformity  to  them  it  will 
be  pleasantly  toned.     Images  and  concepts  also  conform  to 
this  general  rule.     It  is  doubtful  whether  affection  possesses 
a  memory  of  its  own.     Can  we  image  and  reinstate  our 
affections  as  we  do  our  cognitive  states?     We  can  remember 
that  certain  past  experiences  v/ere  agreeable  or  disagreeable, 
but  this  process  is  purely  cognitive,  not  affective.     Memory 
involves  imagery,  and  images  are  possible  only  as  cognitive 
p/oducts.     Affection  is  always  a  first-hapd  product,  arising 
*t*«tresh  from  the  nature  of  the  cognitive  processes  at  the  present 
moment  and  never  the  image  or  reproduction  of  a  previous 
state. 

Over  and  above  the  affective  states  which  accompany 
^he  separable  cognitive  elements  in  the  intellectual  process, 
a    further    affective   coloring  may  adhere   to    the   thinking 
^u^]f^\       process  itself.     Here  the  same  general  principle,  which  we 
(,,  found  governing  the  affective  states  in  memory  and  imagina- 

tion, holds  in  the  processes  of  thought.  Reasoning  processes 
which  aid  our  purposes,  interests,  and  desires,  are  agreeably 
toned,  while  those  which  oppose  them  are  disagreeably  toned. 
Affection  and  Bodily  Expressions. — Attempts  have  been 
made  to  find  the  characteristic  bodily  reactions  which  are 
connected  with  agreeableness  and  disagreeableness— such 
bodily  reaction  as  changes  in  circulation,  respiration,  secre- 
tions, digestion,  and  involuntary  movements.  Changes  in 
respiration  during  both  agreeable  and  disagreeable  experiences 
have  been  studied  by  means  of  the  pneurnograph — an  instru- 
ment which  records  the  rate  and  depth  of  breathing.  Varia- 
tions in  the  pulse  have  been  recorded  by  the  sphvgmograph. 
and  changes  in  the  volume  of  the  arm  or  other  members 
of  the  body  by  the  pie thysmograph .  The  results  of  these 


AFFECTION   AND   FEELING  305 

studies  of  the  bodily  expressions  connected  with  pleasantness 
and  unpleasantness  are  conflicting.  Changes  in  respiration, 
heart-beat,  gland  activities,  and  involuntary  movements  have 
been  observed  during  the  experiences  of  pleasantness  and 
unpleasantness.  Breathing  may  be  increased  or  decreased 
in  rate  and  depth,  the  pulse  may  be  quickened  or  slowed, 
strengthened  or  weakened,  etc.,  but  no  one  set  of  these 
changes  is  found  to  take  place  uniformly  with  either  one  of  the 
affections.  More  recently  the  galvanometer  has  been  used 
to  detect  the  presence  of  electrical  currents  in  the  body 
during  affective  experiences.  The  discovery  of  these  cur- 
rents in  the  body  was  thought  to  be  the  beginning  of  a  new 
era  in  the  study  of  the  expressions  of  affective  and  emotional 
states.  Cognitive  activity  was  found  to  be  accompanied  by 
only  slight  electrical  changes  while  affective  states  manifested 
their  presence  much  more  markedly.  But  when  we  consider 
that  muscular  activity  may  produce  electrical  changes  similar 
to  those  found  accompanying  affective  states  we  must  con- 
clude that  electrical  phenomena  are  not  distinctive  marks 
of  affective  expression.  Moreover,  these  electrical  changes 
do  not  differ  in  character  for  the  two  forms  of  affection. 
Later  investigations  indicate  that  the  action  of  the  sweat- 
glands  have  something  to  do  with  the  electrical  changes 
recorded  by  the  galvanometer.  Increased  humidity  of  the 
bodily  surfaces  would  certainly  favor  the  passage  of  electri- 
cal currents  from  one  part  of  the  body  to  another. 

In  regard  to  the  grosser  form  of  expression  and  behavior 
accompanying  affective  states,  ordinary  observation  has  lit- 
tle difficulty  in  detecting  the  difference  in  the  facial  expres- 
sions and  bodily  attitudes  which  attend  the  affective  state 
of  pleasantness  and  those  which  attend  the  affective  state 
of  unpleasantness.  We  know  immediately  when  our  friends 
are  pleased  and  when  they  are  displeased.  In  a  general  way  > 
we  may  say  that  pleasurable  experience  tends  to  bodily  move- 
ments of  expansion  and  approach,  while  unpleasant  experi- 
ences tend  to  movements  of  contraction  and  withdrawal. 


366 


PSYCHOLOGY 


There  can  be  no  question  but  that  all  the  vital  processes,  even 
those  of  assimilation,  secretion,  and  excretion,  are  influenced 
during  affective  experiences;  but,  beyond  the  very  general 
statement  which  we  have  already  made,  we  are  unable  to 
formulate  any  law  which  governs  the  affective  bodily  ex- 
pressions. 

Neural  Basis  of  Affection.  —  Sensations  depend  upon  the 
action  of  specific  nerves  and  brain  centres.  There  are,  how- 
ever, no  special  end-organs  and  brain  centres  for  pleasantness 
and  unpleasantness.  What,  then,  is  the  neural  basis  of  affec- 
tion ?  We  have  no  exact  detailed  knowledge  to  offer  in  answer 
to  this  question.  We  must,  therefore,  resort  to  theory.  It 
seems  probable  that  affection  depends  upon  the  mode  in 
which  neural  activity  goes  on  in  any  particular  part  of  the 
nervous  system,  or  upon  the  way  in  which  the  neural  activity 
in  any  one  part  affects  the  other  parts  of  the  nervous  system 
or  the  nervous  system  as  a  whole.  Normal  and  efficient 
reaction  of  the  neural  mechanism  in  any  particular  segment 
corresponds  to  pleasantness,  while  excessive  or  inefficient  re- 
action corresponds  to  unpleasantness.  This  would  explain 
the  disagreeable  character  of  very  high  and  very  low  sense 
intensities. 

We  must  admit  that  this  principle  is  difficult  to  apply  in 
cases  where  unpleasantness  is  due  either  to  the  quality  of 
sensations  or  to  ideational  processes.  Why,  for  instance,  is 
the  moderate  intensity  of  bitter  unpleasant?  Or  why  is 
the  perfectly  clear  and  definite  thought  of  a  friend's  disloyalty 
unpleasant  ?  In  the  case  of  the  sensation  bitter  we  may  sup- 
pose that  the  nerve-tissues  involved  are  not  adapted  to  the 
stimulus  —  that  the  nerve-currents  caused  by  the  stimulus  are 
of  such  a  nature  that  they  meet  resistance  in  the  nervous 
tissue  of  the  sense  pathways  and  centres.  In  the  case  of 
the  thought  of  the  friend's  disloyalty  the  resistance  would  be 
found  in  the  association  paths  and  centres.  Thus  the  theory 
of  resistance  may  be  applied  to  all  cases  of  affection  ac- 
companying both  sensory  and  ideational  processes.  Ziehen 


AFFECTION   AND   FEELING 


proposes  such  a  theory.  He  holds  that  the  normal  and  e 
cient  discharge  of  nerve-currents  from  any  part  of  the  brain, 
along  paths  of  projection,  or  paths  of  association,  is  the  neural 
counterpart  of  pleasantness,  while  any  obstruction  of  such 
discharge  is  the  counterpart  of  unpleasantness.  In  short, 
pleasantness  goes  with  facilitation  and  unpleasantness  with 
inhibition  of  neural  activity.  It  is  interesting  to  compare 
with  this  physiological  tneory  of  affection  the  old  intellec- 
tualistic  theory  that  pleasantness  is  the  awareness  of  the 
harmonious  co-operation  of  ideas,  and  that  unpleasantness  is 
the  awareness  of  the  conflict  between  ideas — in  other  words, 
that  affection  is  brought  about  by  the  facilitation  and  inhibi- 
tion of  ideas  among  themselves.  Since  we  are  committed  to 
the  hypothesis  that  every  form  of  consciousness  has  a  neural 
basis  of  some  kind,  we  must,  therefore,  consider  the  neural 
as  well  as  the  mental  conditions  under  which  affection  arises. 
The  conditions  of  resistance  affecting  the  mode  of  activity 
in  nerve  pathway  and  centres  may  then  be  taken  as  the 
neural  basis  of  affection.  Many  other  theories  have  been 
proposed.  Bain's  statement  of  the  case  may  be  translated 
into  neural  terms.  He  says  that  "states  of  pleasure  are  con- 
nected with  an  increase,  and  states  of  pain  with  an  abatement, 
of  some  or  all  of  the  vital  functions."  This,  of  course,  is  true 
in  many  instances,  but  it  does  not  always  hold.  Cases  may 
be  found  where  pleasure  is  the  accompaniment  of  lessened 
vital  functions. 

Titchener  thinks  that  the  free  sensory  nerve-endings  found 
throughout  the  different  tissues  of  the  body  are  the  peripheral 
organs  of  affection.  They  represent,  he  thinks,  "a  lower  level 
of  organic  development  than  the  specialized  receptive  organs, 
or  organs  of  sense.  Had  mental  development  been  carried 
further,  pleasantness  and  unpleasantness  might  have  become 
sensations — in  all  likelihood  would  have  developed  into  a  num- 
ber of  sensory  qualities."  Back  of  this  hypothesis  lies  the 
theory  that  sensations  and  affection  have  both  developed  from 
a  common  mental  ancestor — a  kind  of  undifferentiated  con- 


^ 
v</ 


368  PSYCHOLOGY 

sciousness.     He  says  that  "the  affections  appear — not  ex- 

\actly  as  undeveloped  sensations — but  at  any  rate  as  men- 

Ital  processes  of  the  same  general  kind  as  sensations,  and  as 

I  mental  processes  that  might  in  more  favorable  circumstances 

have  developed  into  sensations." 

The  exact  function  of  the  free  nerve-endings  is  in  dispute. 
We  have  in  our  treatment  of  sensation  considered  them  as 
sense  end-organs  whose  stimulation  results  in  pain.  There 
is  nothing  impossible,  however,  in  the  supposition  that  there 
are  undifferentiated  free  nerve-endings  within  the  tissues  of 
the  body  which  may  give  rise  to  certain  affective  experiences. 
It  is,  however,  difficult  to  see  how  the  affections  accompany- 
ing ideational  processes  can  be  accounted  for  by  such  nerve- 
endings. 

Certain  writers  connect  affection  with  the  action  of  special 
cortical  centres  in  the  brain,  others,  like  Meynert,  connect 
affection  with  the  nutritive  condition  of  the  brain.  But 
where  definite  facts  are  wanting  it  is  useless  to  attempt  to 
,  evaluate  these  theories.  Lehmann  considers  pleasantness  cor- 
|  related  to  the  proper  balance  between  the  supply  and  the 
!  expenditure  of  energy  by  the  nerve-cells  in  the  brain;  while 
unpleasantness  is  the  correlate  of  an  excess  of  expenditure 
over  supply.  Very  intense  stimuli  are  disagreeable  because 
they  overwork  the  brain-cells  and  call  for  a  greater  expendi- 
ture of  nervous  energy  than  can  be  supplied  by  the  nutritive 
process  in  the  centres  involved.  Miinsterberg  suggests  what 
he  calls  the  " action  theory"  of  affection.  Pleasantness  is 
the  correlate  of  central  brain  activity  which  is  starting  bodily 
movements  of  approach,  while  unpleasantness  is  the  correlate 
of  central  brain  activity  which  is  starting  movements  of  with- 
drawal. Affection,  therefore,  is  the  conscious  accompani- 
ment of  central  brain  processes  connected  with  the  arousal 
of  movement  impulses. 

The  Significance  and  Function  of  Affection. — When  we 
review  the  facts  of  our  affective  consciousness  we  see  that 
we  are  justified  in  believing  that  pleasantness  is  correlated 


AFFECTION  AND   FEELING 
with  those  conditions  both  within 


_  ^ 

Tts^welfare;    while  unpleasantness"*  is 


correlated  with  those  conditions  that  menace  its  welfare. 
In  the  main  whatever  is  immediately  beneficial  is  agreeable 
and  whatever  is  immediately  harmful  is  disagreeable.  In 
a  complex  organism  like  that  of  man  the  application  of  this 
principle  meets  with  many  difficulties  for  the  reason  that 
sometimes  what  is  beneficial  to  some  one  phase  of  his  existence 
is  harmful  to  another,  and  what  is  helpful  for  the  immediate 
moment  is  detrimental  in  the  long  run.  Affection,  then,  , 
may  be  looked  upon  as  an  index  of  f-bp  iT 


that_are  beneficial  or  harmful  to  the  organism. 

There  seems  to  be  no  doubt  of  the  fact  that  pleasantness 
determines  apportion  —  the  tendency  to  hold  to  certain  stimuli 
and  continue  certain  experiences,  and  that  unpleasantness 
determines  aversion  —  the  tendency  to  withdraw  from  cer- 
tain stimuli.  The  reactions  involved  in  appetition  and 
aversion  are  the  most  fundamental  and  significant  selective 
reactions  of  the  organism.  It  may  be  true  that  in  man's 
higher  development  some  of  his  reactions  are  not  determined 
by  the  agreeable  or  disagreeable,  but  in  his  primitive  forms  of 
behavior,  at  least,  he  seeks  the  pleasant  and  avoids  the 
unpleasant.  If,  now,  the  pleasant  is  connected  with  the 
beneficial  and  unpleasantness  with  the  harmful,  we  can  see 
of  what  far-reaching  biological  significance  the  affective  con- 
sciousness must  have  been  in  organic  development.  Organ- 
isms which  in  the  beginning  sought  the  pleasant  must  have  had 
a  tremendous  advantage  over  those  which  did  not.  To  the 
question  as  to  how  the  connection  between  the  beneficial 
and  the  pleasant  experiences  was  established  we  are  unable 
to  offer  an  answer  in  psychology.  That  is  a  question  which 
the  biologists  have  not  yet  settled.  Were  the  first  organisms 
as  likely  to  seek  stimuli  giving  unpleasant  experiences  as  those 
giving  pleasant  experiences?  Did  natural  selection  by 
killing  off  those  who  sought  the  unpleasant  establish  the 
tendency  in  the  race  to  seek  the  pleasant?  If  this  is  true 


370  PSYCHOLOGY 

then  we  must  suppose  that  the  relation  between  the  pleasant 
and  the  beneficial  and  between  the  unpleasant  and  the  harm- 
l  ful  stimuli  were  already  established  in  the  very  beginning. 
Some  psychologists,  perhaps,  would  prefer  to  disregard  con- 
sciousness altogether  as  a  factor  in  evolution.  Natural  se- 
lection would  then  preserve  those  organisms  which  happened 
to  seek  beneficial  stimuli  and  eliminate  those  that  happened  to 
seek  harmful  stimuli.  Consciousness  in  such  a  scheme 
would  have  nothing  to  do  with  organic  development.  In 
this  case  the  tendency  to  seek  the  beneficial  and  avoid  the 
harmful  must  have  grown  up  through  natural  selection  inde- 
pendently of  the  consciousness  of  pleasantness  and  unpleasant- 
ness. It  is,  however,  inconceivable  that  so  important  a  fac- 
tor as  consciousness  has  had  nothing  to  do  with  behavior.  We 
cannot  give  up  the  principle  previously  postulated,  viz. :  that 
the  affective  states  of  pleasantness  and  unpleasantness  have 
been  and  still  are  in  a  large  measure  efficient  factors  in  the 
struggle  for  existence.  We  are  willing,  therefore,  to  accept 
the  hypothesis  that  beneficial  stimuli  were  from  the  very 
first  capable  of  giving  the  experience  of  pleasantness  and 
harmful  stimuli  the  experience  of  unpleasantness. 

Feeling. — While  feeling  is  a  complex  mental  state  con- 
\  taming  cognitive  elements,  the  predominating  character  of 
/  the  experience  is  given  to  it  by  its  affective  components.     Pain, 
/  for  instance,  although  a  sensation,  is  often  properly  spoken  of 
as  a  feeling,  because  the  total  experience  is  predominantly 
affective.    Hunger  too  may  be  referred  to  as  a  feeling  when 
we  mean  to  include  the  affection  accompanying  its  sensory 
process.     Many  of  the  organic  sensations  are  commonly  con- 
sidered to  be  feelings  because  the  sensory  qualities  in  the 
experiences  are  so  vague  and  unclear  that,  failing  to  occupy 
attention,  they  allow  the  affective  consciousness  to  outweigh 
them  in  the  total  experience.     Not  only  do  sensory  elements 
form  nuclei  for  feelings,  but  memories,  images,  and  trains 
of  thoughts  are  oftentimes  so  deeply  submerged  in  affective 
consciousness  that  the  experiences  may  be  termed  feelings. 


AFFECTION  AND   FEELING  371 

Since  sensory  and  ideational  processes  of  various  varie- 
ties and  in  many  degrees  of  intensities  and  duration  may 
combine  with  the  different  qualities  of  affection,  it  is  evident 
that  the  number  of  different  feelings  that  the  human  mind 
can  experience  is  infinitely  great.  They  may  vary  from  the 
very  simple  feelings  involving  only  a  single  sensation,  percept, 
idea,  or  thought  to  the  most  complex  feelings  involving 
highly  complicated  combinations  of  sensory  and  ideational 
elements  and  mental  activities.  The  feeling  of  hunger,  of 
pain,  or  that  aroused  by  a  pure  spectral  color  or  by  the  thought 
of  honesty  are  simple  feelings,  while  that  aroused  by  a  sym- 
phony, the  Sistine  Madonna,  or  by  the  tragedy  of  " Hamlet" 
are  very  complex  feelings.  Feelings  may  also  vary  from  the 
relatively  pure  to  those  that  are  highly  mixed.  All  the 
elements  in  a  situation  may  arouse  the  same  kind  of  affection. 
On  the  other  hand,  some  of  the  elements  may  be  disagreeable 
while  the  others  may  be  agreeable.  The  resultant  feeling  in 
the  first  case  is  pure  while  the  feeling  in  the  second  case  is 
mixed.  The  feeling  aroused  by  a  beautiful  landscape  is  pure. 
Every  part  of  the  whole — the  several  objects,  colors,  etc. — 
is  agreeable,  as  is  also  the  synthesis  of  these  parts  into  the 
whole.  But  the  feeling  which  stirs  us  when  we  contemplate 
Shakespeare's  tragedy  "Hamlet"  is  a  mixed  feeling;  for  while 
some  of  the  separable  contents  of  our  thought  are  unpleasantly 
and  some  pleasantly  toned,  the  artistic  combination  of  the 
parts  into  a  whole  may  produce  a  decidedly  pleasant  effect. 
It  is  evident  that  the  complex  feelings  may  be  either  pure 
or  mixed  accordingly  as  they  contain  affections  of  the  same 
or  of  different  qualities.  The  simple  feelings  are  always  pure 
feelings. 

Classification  of  Feelings. — The  classification  of  the  feel- 
ings based  only  upon  the  quality  of  affection  which  enters  into 
them  gives  just  two  kinds  of  feelings:  Pleasant  and  un- 
pleasant feelings.  But  if  we  employ  other  bases  of  classifica- 
tion, many  kinds  of  feelings  may  be  made  out.  In  view  of 
the  great  number  of  combinations  that  may  occur  between 


372  PSYCHOLOGY 

the  elements  of  affection  and  the  different  qualities  and 
intensities  of  sensations  and  of  ideational  processes,  it  is 
impossible  to  make  any  adequate  classification  of  the  feelings. 
We  can  suggest  only  a  few  very  general  divisions. 

As  we  have  already  seen,  if  we  think  of  the  degree  of  com- 
plexity into  which  the  component  parts  of  feeling  enter, 
feelings  may  be  simple  or  complex;  or  pure  and  mixed  if 
we  consider  the  homogeneity  or  heterogeneity  of  the  affec- 
tion qualities  which  enter  into  the  combination. 

Certain  vaguely  localized  and  obscure  organic  sensations 
have  sometimes  been  spoken  of  as  sensus  communis  or  "com- 
mon feelings."  These  sensations  arise  from  changes  in  blood- 
supply  in  the  capillaries  about  nerve-endings,  from  the  physi- 
ological condition  and  action  of  heart,  lungs,  glands,  and  other 
internal  organs — in  short  these  sensations  constitute  the 
vague  awareness  we  have  of  the  condition  of  inner  organic 
processes.  This  awareness  is  never  raised  to  definite  and 
clear  presentations  of  sense  and  for  this  reason  the  sensa- 
'tions  referred  to  appear  to  be  almost  entirely  affective  in 
>^  nature.  They  do  possess  affective  tone  and  the  mixture  of 
obscure  sensations  and  affection  result  in  the  common  feelings. 
I  Feelings  of  well-being,  of  higft  spirits,  of  derj^essioii,  of  glnnm 
1  and  despondency  belong  to  this  class  of  common  feelings. 
'  Although~They  usually  remain  in  the  background  of  conscious- 
N^<!{  ness,  they  may  give  tone  and  color  to  the  entire  stream  of 

consciousness.  They  are  not  only  important  in  determining 
.  <j  I  our  moods  but  they  also  contribute  very  largely  to  the  con- 
v\  \sciousness  of  self.  Temporary  and  often  slight  functional 
disturbances  in  the  vital  processes  may  result  in  a  personal 
"feeling  of  strangeness"  or  a  "feeling  of  not  like  ourselves" 
without  our  knowing  why.  The  common  feelings  are  differen- 
tiated from  the  feeling  which  arises  in  connection  with  the 
special  senses,  or  with  the  ideational  process,  by  the  obscure- 
ness  of  their  cognitive  elements. 

Feelings  may  be  classified  into  sensuous  and  intellectual 
feelings  accordingly  as  their  cognitive  contents  result  from 


*     *vw       /fl  / 


AFFECTION   AND   FEELING  373 


the  sensory  or  the  ideational  processes.  But  since  ideational 
processes  depend  upon  and  involve  sensory  elements  this 
classification  is  not  a  very  valuable  one. 

If  we  were  to  classify  the  feelings  according  to  the  nature 
of  the  cognitive  states  which  enter  into  them,  the  list  of  feel- 
ings would  be  as  long  as  that  of  the  cognitive  states  them- 
selves. Some  of  our  presentations  and  trains  of  thought, 
however,  are  especially  prolific  in  producing  affective  states. 
Esthetics,  ethics,  social  relationships,  and  religion  involve 
presentations,  ideas,  and  thoughts  which  enter  into  feeling 
complexes.  It  is  suggested,  therefore,  that  we  classify  feelings 
into  (esthetic  feelings ,  ethicaJ-feeltfigs,  social  feelings,  and  relig- 
ious feeT/ingsT  This,  however,  is  a  very  partial  and  incom- 
plete classirication.  There  are  many  other  cognitive  experi- 
ences which  are  capable  of  arousing  affections. 

Mood. — We  often  find  that  for  considerable  periods  of 
time  the  stream  of  consciousness  is  permeated  by  a  more  or 
less  persistent  affective  tone.  All  our  presentations  and 
thoughts  are  temporarily  colored  by  a  certain  affective  atti- 
tude. This  predisposition  to  feel  in  a  certain  way  is  known 
as  mood.  For  hours  after  receiving  a  bit  of  good  news  we  may 
be  dominated  by  the  feeling  of  cheerfulness.  Even  disagree- 
able experiences  are  transformed  and  lose  their  irritating 
character  under  the  spell  of  this  mood.  On  the  other  hand, 
bad  news  or  an  especially  irritating  experience  may  leave  us 
with  the  "blues."  Moods  are  not  only  the  after-effects  of 
past  events  and  past  feelings,  but  they  may  be  induced  by 
intra-organic  conditions.  Blooming  health  predisposes  to 
cheerfulness,  while  indigestion  or  other  physiological  dis- 
turbances may  depress  us  and  make  the  whole  world  seem 
out  of  joint.  Sometimes  we  pass  from  one  mood  to  another 
very  quickly,  at  other  times  the  change  takes  place  very 
slowly. 

Temperament. — While  mood  is  a  temporary  disposition 
to  feel  in  a  certain  way,  temperament  is  a  fixed  and  permanent 
predisposition  toward  a  definite  form  of  affective  response. 


374  PSYCHOLOGY 

Individuals  differ  markedly  j£i  this  respect.  Some  are  so 
constituted  that  everything  appears  in  a  gloomy  and  melan- 
choly light,  while  others  are  constitutionally  predisposed  to 
view  everything  in  the  brightest  hues.  These  differences 
in  temperament  are  probably  due  to  hereditary  factors  and 
represent  in  each  individual  permanent  tendencies  in  his 
feeling  attitudes.  A  very  old  and  well-known  classification 
of  temperaments  divides  them  into  four  classes  accordingly 
as  their  feeling  responses  are  quickly  or  slowly  aroused  and 
whether  they  are  intense  or  weak  in  character.  These  forms 
of  temperament  are  choleric,  melancholic,  sanguine,  and 
phlegmatic.  , 

The  choleric  temperament  has  quickly  aroused  and 
intense  feelings,  the  melancholic  has  slowly  aroused  and 
intense  feelings,  the  sanguine  has  quickly  aroused  and  weak 
feelings  and  the  phlegmatic  has  slowly  aroused  and  weak 
feelings. 

Emotions. — There  are  certain  complex  and  mixed  feelings 
possessing  a  higl^  degree  of  intensity  and  vividness,  which 
are  known  as  emotions.  They  might  be  referred  to  as  jeel- 
ings  of  agitation.  Tney  are  conditioned  by  a  series  of  wide- 
spread and  diffuse  Organic  excitations,  conflicting  instinctive 
impulses,  and  habitual  types  of  reaction.  On  the  cognitive 
side  they  contain  tfee  perception  or  ideation  of  certain  excit- 
ing objects  and  events  plus  a  mass  of  kinaesthetic  and  organic 
sensations  which  are  aroused  by  the  organic  excitation  and 
the  conflicting  instinctive  impulses  and  reactions.  The  af- 
fective states  accompanying  these  various  cognitive  states  en- 
tering into  the  tot£l  complex  are,  therefore,  numerous  and 
conflicting.  Iff  all  the  other  feelings  the  stream  of  cognitive 
consciousness  is  not  especially  disturbed — the  various  processes 
of  presentation  and  currents  of  thought  go  on  more  or  less 
smoothly  and  without  marked  interruption,  but  in  emotions 
there  is  a  sudden  stoppage  in  all  the  avenues  of  mental  activ- 
ity. Especially  is  there  a  blocking  of  the  higher  cognitive 
activities.  We  are  seized,  as  it  were,  by  emotions. 


AFFECTION  AND  FEELING  375 


neural  excitement  caused  by  an  emotional  o^j^t  or 
fails  to  be  adequately  drained  off  through  the  usual  channels 
oradjustmpntr  AsH  consequence  the  nervous  energy  aroused 
is  turned  back  into  the  organism  and  diffused  throughout 
the  organic  and  motor  pathways,  thereby  causing  a  condi- 
tion of  conflicting  bodily  impulses.  Anger  and  fear  are 
typical  emotions.  Since  we  shall  return  to  the  study  of 
emotions  in  the  next  chapter,  we  shall  give  no  more  space  to 
their  consideration  here.  We  have  mentioned  them  only 
to  point  out  their  place  among  the  feelings. 

Sentiments.  —  Sentiments  are  relatively  permanent  feelj 
ings  which  grow  up  around  more  or  less  complete  systems  ol 
ideas  and  intellectual  processes.  A  sentiment  might  be  called 
a  frame  of  mind  colored  and  supported  by  affective  conscious- 
ness. Baldwin's  "  Dictionary  of  Philosophy  and  Psychology" 
defines  sentiments  as  "emotional  dispositions  having  refer- 
ence  to  an  object  or  class  of  objects  represented  by  a  more 
or  less  complex  system  of  ideas."  They  are,  however,  milder 
and  more  enduring  feelings  than  emotions.  They  are  feel- 
ings which  are  based  upon  and  include  a  more  rational  cogni- 
tive process  than  emotions.  They  vary,  however,  in  this 
respect,  sometimes  more  and  sometimes  less  of  the  rational 
element  being  present.  They  may  at  times  under  certain 
circumstances  rise  to  the  same  intensity  and  take  on  the 
irrational  and  agitating  character  of  emotions.  Love,  for 
instance,  is  both  a  sentiment  and  an  emotion.  As  a  sentiment 
it  includes  a  rationalized  system  of  ideas  and  the  affective 
tone  which  attaches  to  the  ideas.  As  an  emotion  these 
ideas  temporarily  sink  into  the  background  while  we  are 
thrilled  in  every  nerve  by  the  object  of  the  emotion.  Friend- 
ship is  a  typical  sentiment.  Here  we  find  the  mental  pres- 
entations of  the  personal  vir  tues^  and  'characteristics.  of  £he 
^object  of  friendship  and  the  experienced  conformity  of  these 
characteristics  to  certain  ideals  which  have  been  formulated 
and  fixed  in  our  minds.  A  sentiment  is  not  experienced  in 
its  entirety  at  any  one  moment;  it  follows  in  its  activity  the 


376  PSYCHOLOGY 

sequence  of  ideas  which  centre  about  its  object  and  so  only 
one  phase  of  the  sentiment  is  active  at  a  time.  In  so  far, 
however,  as  we  are  able  to  unify  all  the  various  ideas  into  a 
single  concept,  the  sentiment  too  may  be  unified  into  a  momen- 
tary experience. 

Since  sentiments  form  about  relatively  stable  centres  of 
ideas  and  intellectual  processes,  we  may  expect  to  find  most 
authorities  classifying  them  according  to  certain  fields  of 
experience  in  which  we  have  established  ideals,  or  norms.  We 
have,  for  instance,  ideals  of  truth,  of  right,  of  beauty,  and  of 
the  Absolute.  Ideational  constructions  which  are  conform- 
able or  non-conformable  to  such  ideals  would  constitute  the 
bases  for  the  different  kinds  of  sentiments.  Accordingly, 
sentiments  are  divided  into  (i)  intellectual  or  logical,  (2) 
ethical  or  social,  (3)  (esthetic,  and  (4)  religious  sentiments. 
Among  intellectual  sentiments  may  be  mentioned  those  of 
belief  and  disbelief,  of  truth  and  falsehood,  of  agreement 
and  contradiction.  The  ethical  sentiments  include  those  of 
friendship,  hate,  pride,  freedom,  and  gratitude.  The  aesthetic 
sentiments  include  the  sentiments  of  beauty  and  ugliness,  of 
sublimity  and  tragedy.  Among  the  religious  sentiments 
are  those  of  awe,  reverence,  faith,  and  remorse. 

Passion. — The  term  passion  is  very  loosely  used  in  ordi- 
nary speech.  Sometimes  it  may  refer  to  a  sentiment;  as  when 
we  say  that  one  has  "a  passion  for  painting."  Sometimes 
it  refers  to  a  strong  and  uncontrolled  emotion.  In  psychology 
the  second  usage  is  prevalent.  But  really  no  sharp  line  be- 
tween emotions  and  passions  can  be  made  out.  We  speak 
of  an  emotion  as  a  passion  when  it  takes  possession  of  us 
to  such  an  extent  that  all  our  powers  of  voluntary  control  are 
inhibited. 


t 


CHAPTER   XVII 
EMOTIONS 

In  the  preceding  chapter  we  said  that  emotions  are  highly 
complex  feelings.  While  a  simple  feeling  manifests  only  a 
single  cognitive  element  and  its  affective  accompaniment, 
emotion,  on  the  other  hand,  is  a  highly  complicated  and 
diffused  reaction  of  the  whole  conscious  organism  in  which 
many  cognitive  and  affective  elements  are  fused  together. 
Before  elaborating  this  theory  of  the  emotions  we  may  prof- 
itably examine  a  very  suggestive  theory  of  emotions  proposed 
in  this  country  by  William  James  and  in  Europe  by  C.  Lange, 
professor  of  medicine  in  Copenhagen.  These  writers,  working 
independently  of  each  other,  came  to  practically  the  same  con- 
clusions. For  that  reason  the  theory  is  known  as  the  "  James- 
Lange  Theory  of  Emotions." 

James-Lange  Theory  of  Emotions. — Speaking  of  the  emo- 
tions of  grief,  fear,  and  anger,  James  says:  "Our  natural  way 
of  thinking  about  these  coarser  emotions  is  that  the  mental 
perception  of  some  fact  excites  the  mental  affection  called  the 
emotion,  and  that  this  latter  state  of  mind  gives  rise  to  the 
bodily  expression.  My  theory,  on  the  contrary,  is  that  theft 
bodily  changes  follow  directly  the  perception  of  the  exciting  fact,  Jj 
and  that  our  feeling  of  the  changes  as  they  occur  is  the  emotion.\\ 
Common  sense  says,  we  lose  our  fortune,  are  sorry  and  weep; 
we  meet  a  bear,  are  frightened  and  run;  we  are  insulted  by  a 
rival,  are  angry  and  strike.  The  hypothesis  here  to  be  de- 
fended says  that  this  order  of  sequence  is  incorrect,  that 
the  one  mental  state  is  not  immediately  induced  by  the 
other,  that  the  bodily  manifestations  must  first  be  interposed 
between,  and  that  the  more  rational  statement  is  that  we  feel 
sorry  because  we  cry,  angry  because  we  strike,  afraid  because 

377 


378 


PSYCHOLOGY 


we  tremble,  and  not  that  we  cry,  strike,  or  tremble,  because 
we  are  sorry,  angry,  or  fearful,  as  the  case  may  be.  Without 
the  bodily  states  following  on  the  perception,  the  latter  would 
be  purely  cognitive  in  form,  pale,  colorless,  destitute  of 
emotional  warmth.  We  might  then  see  the  bear,  and  judge 
it  best  to  run,  receive  the  insult,  and  deem  it  right  to  strike, 
but  we  should  not  actually  feel  afraid  or  angry.  .  .  .  No 
reader  will  be  inclined  to  doubt  the  fact  that  objects  do  excite 
bodily  changes  by  a  preorganized  mechanism,  or  the  further 
fact  that  the  changes  are  so  indefinitely  numerous  and  subtle 
that  the  entire  organism  may  be  called  a  sounding-board,  which 
every  change  of  consciousness,  however  slight,  may  make 
reverberate.  .  .  .  Every  one  of  the  bodily  changes,  whatever 
it  be,  is  felt  acutely  or  obscurely,  the  moment  it  occurs."1 

is  statement  makes  emotion  a  group  of  organic  sensa- 
reflexly  excited  by  the  emotional  object  or  situation, 
o  place  is  given  in  the  theory  to  the  various  shadings  and 
combinations  of  the  affections  of  pleasantness  and  unpleasant- 
ness which  enter  into  and  give  affective  character  to  the  feel- 
ings.    The  theory  also  denies  the  very  widely  accepted  belief 
that  the  primary  central  excitation  reaching  the  brain  from 
external  objects  or  events  is  the  basis  of  emotion.     Neither 
i   the  perception  nor  the  ideation  of  an  emotional  object  or  event 
"71  is  in  itself  able  to  arouse  an  emotion.     Not  until  the  secon- 
1  dary  stimulation  or  organic  back-flow  reaches  the  central  brain 
'  areas  does  the  emotion  arise.     The  theory,  therefore,  calls 
attention  in  a  unique,  way  to  two  very  important  facts  which 
have  been  neglected  by  the  common-sense  view  of  the  emo- 
tions.    In  the  first  place,  we  must  agree  that  exciting  facts 
and  situations  (emotional  stimuli)  do  set  up  instinctive  re- 
flexes in  the  vital  organs  and  in  the  muscles  of  the  body. 
The  sight  of  a  wild  beast  causes  us  to  start  and  tremble 
before  we  have  had  time  to  image  the  danger.     The  shortened 
breath,  the  pallid  face,  and  the  "heart  jumps"  are  immediate 
instinctive  reflexes  which  precede  the  feeling  of  terror  which 

'"Principles  of  Psychology,"  II,  pp.  449-451. 


EMOTIONS  379 

seizes  us.  The  proffered  insult  immediately  closes  our 
fists  and  sets  our  teeth.  The  piece  of  bad  news  reflexly 
causes  the  lachrymal  effusion.  The  embarrassing  situation 
causes  the  reflex  of  swallowing,  of  clearing  the  throat,  or 
of  incipient  coughing.  As  James  says:  "Emotional  objects 
are  certainly  the  primitive  arousers  of  instinctive  reflex 
movements."  In  the  second  place,  we  do  sense  these  bodily 
reverberations  as  organic  and  kinaesthetic  sensations,  some- 
times acutely  and  sometimes  obscurely,  during  the  course 
of  the  emotion.  We,  therefore,  agree  that  these  bodily 
reverberations  are  important  elements  in  the  make-up  of 
the  emotional  seizure.  We  hold,  however,  that  the  theory  is 
illogical  in  that  it  takes  a  part  for  the  whole.  Can  we  agree 
to  the  statement  that  the  complex  of  organic  and  kinaesthetic 
sensations  is  the  emotion  ? 

James  proposes  two  lines  of  argument  in  support  of  his 
theory.  The  first  one  is  as  follows:  "//,"  he  says,  "we  fancy 
some  strong  emotion,  and  then  try  to  abstract  from  our  con- 
sciousness of  it  all  the  feelings  of  the  bodily  symptoms,  we  find 
we  have  nothing  left  behind,  no  'mind-stuff'  out  of  which  the 
emotion  can  be  constituted,  and  that  a  cold  and  neutral  state 
of  intellectual  perception  is  all  that  remains.  .  .  .  What 
kind  of  an  emotion  of  fear  would  be  left  if  the  feeling  neither 
of  quickened  heart-beats  nor  of  shallow  breathing,  neither 
of  trembling  lips  nor  of  weakened  limbs,  neither  of  goose- 
flesh  nor  of  visceral  stirrings,  were  present,  it  would  be  quite 
impossible  for  me  to  think.  Can  one  fancy  the  state  of  rage 
and  picture  no  ebullition  in  the  chest,  no  flushing  of  the  face, 
no  dilatation  of  the  nostrils,  no  clenching  of  the  teeth,  no  im- 
pulse to  vigorous  action,  but  in  their  stead  limp  muscles,  calm 
breathing,  and  a  placid  face?"1  James  asserts  that  he  can 
imagine  no  such  condition — that  without  the  first  set  of  bodily 
excitations  "the  rage  is  as  completely  evaporated  as  the  sen- 
sations of  its  so-called  manifestations"  and  that  the  only 
thing  that  can  take  its  place  is  a  cold-blooded  cognitive  con- 

1  "Principles  of  Psychology,"  II,  pp.  451-452. 


380  PSYCHOLOGY 

sciousness.     He   goes   on   to   say:     "A   purely   disembodied 
human  emotion  is  a  nonentity.     I  do  not  say  that  it  is  a 
contradiction  in  the  nature  of  things,  or  that  pure  spirits  are 
necessarily  condemned  to  cold  intellectual  lives;    but  I  say 
that  for  us,  emotion  dissociated  from  all  bodily  feeling  is 
inconceivable."     Critics  have  already  pointed  out  the  illogical 
nature    of    this    argument.     The  bodily   organic   sensations 
might  well  form  an  important  or  necessary  part  in  emo- 
tion and  yet  not  be   the  emotion.     It  may  be   impossible 
/j  for  emotion  to  exist  without  the  organic  reverberations,  but 
i  /  it  does  not  follow  that  these  reverberations  constitute  the 
'  whole  emotion. 

The  second  line  of  argument  is  based  upon  certain  patho- 
logical cases  found  in  insane  asylums  in  which  emotion  is 
objectless — i.  e.,  cases  where  persons  are  seized  by  morbid  fear 
or  other  emotion  without  cause.  Either  during  or  after  the 
attacks  the  patients  are  unable  to  give  any  reason  for  the 
emotion.  They  are  simply  seized  at  times  by  uncontrollable 
fits  of  fear.  Other  unmotived  emotions — anger,  melancholy — 
may  also  manifest  themselves  and  persist  without  cause. 
If,  according  to  James,  the  patient  is  unable  on  account  of 
some  pathological  nerve  condition  to  take  a  full  breath,  has 
fluttering  of  the  heart  and  visceral  disturbances,  and  mani- 
fests an  irresistible  tendency  to  take  a  crouching  position, 
the  combination  of  the  resulting  organic  sensations  makes 
up  the  emotion  of  morbid  fear.  Assuming  that  in  such  cases 
the  experience  is  a  true  emotion,  there  may  be  ways  of  explain- 
ing it  without  taking  it  for  granted  that  the  combined  group 
of  organic  sensations  is  the  emotion.  First  of  all,  the  patient 
in  his  previous  experience  may  have  had  "fear  thoughts," 
or  real  or  hallucinatory  presentations  of  threatening  things. 
Since  the  organic  sensations  mentioned  would  be  on  these 
occasions  a  part  of  the  emotion,  an  associative  connection 
would  be  set  up  between  the  organic  sensations  and  the  real 
or  imagined  fear  presentations.  We  can  readily  understand, 
then,  how  the  recurrence  of  this  set  of  organic  sensations  can 


EMOTIONS  381 

awaken  the  associative  connections  and  make  active  the 
predisposition  to  the  same  emotional  consciousness.  The 
j/organic  factor  need  not  awaken  the  former  presentations 
f  completely.  These  presentations  may  not  rise  to  full  con- 
sciousness at  all,  but  remain  in  the  background  as  vague 
forebodings,  or  indefinite  and  shadowy  forms  of  threatening 
things  which  remain  hidden  from  the  patients'  introspection. 
Or,  the  organic  sensations  may  be  supplemented  by  meaning. 
In  the  past  experience  of  the  patient,  they  may  have  come  to 
stand  for  fearful  things  in  general.  Again,  we  may  of  course 
refuse  to  accept  the  assumption  that  the  pathological  un- 
motived  fear  is  the  same  as  the  real  emotion  of  fear.  It  may 
be  only  a  remnant  of  the  real  emotion.  These  cases,  there- 
fore, fail  to  furnish  proof  that  the  organic  sensations  are  in 
themselves  the  emotion. 

On  the  other  hand,  attempts  have  been  made  through  ex- 
periments upon  lower  animals  to  show  that  the  organic  sensa- 
tions are  not  necessary  to  emotions.  Sherrington,  for  in- 
stance, by  severing  certain  nerves  in  dogs,  cut  off  all  sensa- 
tions coming  from  the  viscera,  skin,  and  muscles  behind  the 
shoulder.  These  animals  showed  no  loss  of  emotions  after 
the  operation,  so  far  as  could  be  observed.  This,  however,  is 
not  conclusive.  In  the  first  place,  we  know  very  little  about 
the  "inner"  consciousness  of  animals.  We  can  only  observe 
their  outer  behavior.  Who  can  tell  whether  the  dog's  affec- 
tive experiences  were  the  same  after  the  loss  of  the  organic 
sensations?  The  outward  behavior  and  organic  responses 
may  have  manifested  no  observable  difference,  but  we  must 
remember  that  these  responses  are  reflex  movements  and 
might  very  well  take  place,  even  though  their  resulting  sen- 
sations were  not  aroused  in  the  animal's  consciousness.  In 
the  second  place,  even  if  we  agree  that  the  emotions  are  pres- 
ent after  the  elimination  of  the  organic  sensations,  the  images 
or  "memory"  of  these  sensations  may  still  be  aroused  by 
virtue  of  the  associative  connections  formed  in  previous 
experiences. 


382  PSYCHOLOGY 

*  Another  objection  to  the  theory  has  been  offered  by  its 
opponents.  The  objection  is  founded  upon  the  fact  that 
different  emotions  may  manifest  the  same  bodily  expressions. 
Thus  we  may  cry  in  extreme  joy  as  well  as  in  sorrow,  or 
tremble  in  anger  as  well  as  in  fear.  If,  say  the  critics,  the 
emotion  is  the  report  in  consciousness  of  bodily  expressions, 
then  the  quality  of  emotions  must  be  determined  by  the 
character  of  the  expressions.  How,  then,  can  the  same  ex- 
pression be  experienced  in  such  different  ways?  Also,  it  is 
urged,  the  same  emotion  may  manifest  on  different  occasions 
very  different  bodily  expressions.  Thus  at  one  tune  in  fear 
we  may  crouch  and  hide  while  at  another  we  may  run  away. 
How,  then,  can  these  quite  different  bodily  expressions  be 
experienced  in  the  same  way  ?  In  reply  to  these  objections 
it  may  be  said  that  a  single  expression  does  not  determine 
the  character  of  the  emotion.  It  is  rather  determined  by  a 
complex  of  bodily  expressions.  Crying  in  sorrow  is  not  its 
only,  or  even  its  fundamental  expression.  Other  more  deeply 
seated  organic  reactions  give  it  its  character.  Surely  there 
may  be  certain  variations  in  the  expressions  of  an  emotion 
without  destroying  its  general  character.  Unhappily  no  one 
has  yet  determined  the  exact  character  of  the  bodily  expres- 

|sions  in  emotion,  or  made  out  any  uniform  correlation  between 
the  emotions  and  their  expressions.  Shepard,  who  has  made 
a  very  careful  study  of  the  changes  in  circulation  and  breath- 
ing during  affective  conscious  states,  concludes  that  no  classi- 
fication of  the  feelings  can  be  made  on  the  basis  of  their  bodily 
expressions.1  We  cannot,  therefore,  be  dogmatic.  We  must 
wait  for  further  evidence. 

It  is  a  commonly  accepted  hypothesis,  and  the  facts  so 
far  as  we  know  them  indicate  that  affection  arises  from  cen- 
tral brain  processes  which  also  give  rise  to  experiences  of  sen- 
sory or  ideational  character.2  Visual,  auditory,  gustatory, 

1  American  Journal  of  Psychology,  1906,  XVII,  p.  522. 

2  There  are  some  divergent  views,  however.     Miinsterberg,  for  instance, 
considers  that  the  affective  states  of  pleasantness  and  unpleasantness  are  the 


EMOTIONS  383 

and  olfactory  stimuli,  as  well  as  organic  and  kinaesthetic 
stimuli  arouse  affective  consciousness.  If  this  is  true,  and  if 
emotions  are  complexes  of  cognitive  and  affective  conscious- 
ness, then  not  only  do  organic  and  kinaesthetic  sensations 
contribute  to  their  make-up,  but  all  the  other  forms  of  con- 
sciousness contribute  their  part,  too.  There  is  no  reason  to 
suppose  that  the  organic  sensations  alone  have  the  power  to 
arouse  emotional  experiences. 

It  may  be  that  the  back-flow  of  organic  sensations  is  a 
very  important  factor  in  emotions,  or  even  that  its  presence 
makes  the  difference  between  the  stronger  emotions  and  the 
simpler  and  calmer  feelings.  The  agitating  nature  of  emo- 
tion is  due,  without  doubt,  to  the  presence  of  organic  dis- 
turbances. But  in  both  cases  (that  of  simple  feelings  and  of 
the  stronger  emotion)  the  manner  in  which  the  sensory  or 
cognitive  stimuli  enter  and  affect  the  central  areas  gives  rise 
to  the  distinctive  affective  components  in  the  emotion. 

The  chief  difference,  therefore,  between  die  theory  as 
originally  outlined  bv_ James  ..and  the  theory  which  is  sup- 
ported here  jies  in  the  number  and  kinds  of  cognitive  states 
admitted  into  the^motjori^and  in  the  value  placed  upon  the 
affective  elements  as  component  parts  of  the  emotion.  James 
limits  the  emotion  to  the  consciousness  of  the  organic  dis- 
turbance, or  bodily  resonance,  set  up  reflexly  by  the  emo- 
tional stimulus.  We_  believe,  on  the  other  hand,  that  the 
perception  of  an  emotional  objector  event  and  the  ideational 
processes  which  are  awakened  by  the  perception  as  well  as 
the  mass  of  organic  sensations  aroused  bythejjodilyreflexes 

mental  correlates  of  nerve-currents  which  reflexly  excite  muscular  movements 
of  extension  and  contraction.  If  the  movements  are  not  reflexly  excited  they 
are  reported  in  consciousness  as  kinaesthetic  or  muscular  sensations,  but  if 
they  are  reflexly  excited  they  appear  as  affection.  This  would  appear  to  fur- 
nish a  basis  for  the  James-Lange  theory.  Organic  disturbances  set  up  through 
reflex  and  instinctive  pathways  would  be  reported  back  to  consciousness  as 
an  emotional  complex.  There  is  no  evidence,  however,  that  James  had  any 
such  hypothesis  in  mind.  On  the  other  hand,  he  considered  the  organic 
rebound  as  a  sensory  process. 


384  PSYCHOLOGY 

enter__into  the  ^emotional  complex.  In  addition,  we  believe 
that  the  various  affective  accompaniments  of  these  cognitive 
factors  also  help  to  determine  the  character  of  the  emotion. 
All  these  components  form  a  synthetic  unity,  which  we  call 
emotion. 

It  is  fair  to  say  that  James  has  modified  the  original 
statement  of  his  theory  somewhat.  This  modification  con- 
sists in  the  first  place  in  the  admission  of  the  affective  nature 

ofjJTP  pfjrfipfi'nn  which  starj^gjp  emotion.  Either  pleasant- 
ness  or  unpleasantness,  he  admits,  may  inhere  in  the  sensa- 
tions and  be  fused  into  the  perception  into  which  they  are 
combined.  In  the  second  place,  he  has  amplified  his  first 
statements  by  explaining  that  it  is  not  the  perception  of  the 
simple  object  alone  that  initiates  emotion,  but  the  perception 
of  a  total  situation  of  which  the  object  is  a  part.  The  object 
may  in  time,  after  we  are  familiar  with  its  context,  become 
capable  of  suggesting  the  total  situation  and  the  suggestion 
may  start  the  emotion. 

The  Instinctive  Reactions  and  Emotions. — If  we  consider 
a  list  of  the  most  important  instincts  we  shall  find  that  they 
all  manifest  an  emotional  aspect.  For  instance,  fear  is  both 
an  instinct  and  an  emotion — an  instinct  in  so  far  as  it  is  a 
tendency  leading  to  native  forms  of  motor  reactions,  such 
as  flight,  crouching,  or  hiding — an  emotion  in  so  far  as  it  is 
a  feeling.  Pugnacity  and  anger,  curiosity  and  wonder,  paren- 
tal instinct  and  tender  emotion  are  other  pairs  of  terms,  the 
first  of  which  stands  for  an  instinct  and  the  second  an  emo- 
.  tion.  Instinctive  situations  tend  to  set  up  emotions  as  well 
I  as"  instincts.  On  the  other  hand,  emotional  stimuli  tend  to 
'  arouse  instinctive  reactions.  The  instincts  which  are  strongly 
marked  by  an  emotional  counterpart,  like  those  of  anger 
and  fear,  manifest,  in  addition  to  their  outward  acts,  motor 
reactions  which  affect  the  inner  organic  processes.  The  in- 
stincts which  are  less  marked  by  emotional  tone,  like  those 
of  play  and  imitation,  manifest  little  or  no  tendency  to  dis- 
turb the  inner  organic  processes.  All  of  their  energy  is  con- 


EMOTIONS  385 

sumed  in  acts  which  affect  outer  objects.  In  so  far,  then,  as 
an  instinct  initiates  motor  impulses  which  affect  primarily 
the  organism,  it  gives  rise  to  emotion,  but  in  so  far  as  it  con- 
sists in  acts  which  change  the  environment  or  in  acts  which 
adjust  the  organism  properly  to  the  environment,  we  think 
of  it  only  as  an  instinct. 

If  we  ask  why  certain  instinctive  impulses  are  thrown 
back  into  organic  channels  instead  of  into  the  more  evident 
environmental  adjusting  mechanism  of  the  body,  we  may 
find  an  answer  in  certain  biological  theories.  The  student 
must  judge  for  himself  the  value  of  these  theories.  Why,  for 
instance,  does  the  mouth  become  dry  and  the  skin  moist  with 
perspiration  in  fear?  Why  do  we  tremble  when  confronted 
with  a  fearful  object  ?  The  answer  which  has  been  commonly 
given  in  explanation  will  be  more  evident  if  we  consider  some 
of  the  other  instinctive  reflexes  found  in  fear.  For  instance, 
we  start  and  crouch  and  shrink  into  ourselves  when  fright- 
ened. The  movements  are  the  initial  stages  of  running  or 
jumping  away,  and  of  hiding  from  the  threatening  object, 
The  movements  of  running  away  and  hiding  have  been  very 
useful  to  the  organism  in  just  such  circumstances.  There- 
fore, the  starting  and  crouching  and  shrinking  in  fear  are 
supposed  to  be  weakened  repetitions  of  useful  acts.  Accord- 
ingly, all  emotional  reactions  which  are  not  now  plainly  use- 
ful are  looked  upon  as  organic  survivals  of  acts  that  were 
once  useful  and  adaptive  reactions  in  racial  development. 
They  are  reminiscent  of  past  struggles  for  existence.  The 
disturbances  in  heart  and  lung  action  which  are  present  in 
fear  are  repetitions  of  the  quickened  heart-beat  and  breath- 
ing needed  in  flight  or  combat.  "Fear,"  says  Spencer, 
"when  strong,  expresses  itself  in  cries,  in  efforts  to  escape, 
in  palpitations,  in  tremblings;  and  these  are  just  the  mani- 
festations that  go  along  with  an  actual  suffering  of  the  evil 
feared.  The  destructive  passion  is  shown  in  a  general  ten- 
sion of  the  muscular  system,  in  gnashing  of  teeth  and  pro- 
trusion of  the  daws,  jrj  dilated  eyes  and  nostrils,  in  growls; 


386  PSYCHOLOGY 

and  these  are  weaker  forms  of  the  actions  that  accompany 
the  killing  of  prey."  Distention  of  the  nostrils  in  anger, 
Spencer  thinks,  is  a  survival  of  the  manner  in  which  our 
ancestors  had  to  breathe  during  combat.  Many  emotional 
expressions  have  been  traced  back  to  early  utilitarian  adap- 
tations. Trembling  in  fear  may  have  been  an  instinctive 
movement  preparatory  to  actual  flight.  The  quickened 
breath  of  anger  harks  back  to  the  times  of  hand-to-hand  con- 
flicts with  an  enemy.  Clenching  the  teeth  and  opening  the 
lips,  which  is  now  often  observed  in  angry  men,  is  a  survival 
of  those  early  struggles  in  which  the  teeth  were  used  for 
attack.  Opening  the  mouth  in  astonishment  was  useful  in 
that  it  aided  in  attentive  listening.  Blushing  of  the  face  and 
neck,  according  to  Wundt,  serves  the  purpose  of  relieving 
the  brain  of  blood-pressure,  which  is  increased  during  certain 
emotional  excitement.  Many  more  illustrations  of  emotional 
reactions  that  were  once  clearly  serviceable  may  be  found. 
Man  has  advanced  beyond  the  stage  where  many  of  the 
originally  serviceable  reactions  are  of  present  utility.  They 
are,  therefore,  not  executed  as  they  once  were.  Modified, 
or  atrophied,  they  now  exist  only  in  weakened  and  rudimen- 
tary form  as  tendencies  to  action,  and  they  fail  to  do  more 
than  stir  up  the  organism.  In  some  cases  they  are  antago- 
nistic to  later-acquired  co-ordinations,  and  are  consequently 
partially  inhibited  or  suppressed. 

While  it  seems  probable  that  certain  emotional  reactions 
can  be  explained  by  the  principle  of  utility,  there  are  others 
which  refuse  to  be  accounted  for  in  this  way.  In  what  way 
can  the  cold  sweat,  nausea,  and  dryness  of  the  mouth  in  fear, 
the  lump  in  the  throat  in  grief,  and  the  swallowing  in  embar- 
rassment, together  with  many  other  organic  excitements,  be 
thought  of  as  derived  from  once-useful  adjustments?  James 
is  of  the  opinion  that  many  of  the  emotional  reactions  are 
"purely  mechanical  or  physiological  outpourings  through  the 
easiest  drainage-channels,"  and  are  to  be  looked  upon  as 
accidental  or  even  pathological  disturbances  rather  than  once- 


EMOTIONS  387 

serviceable  reactions.  Mosso,  who  has  given  the  subject 
much  attention,  also  thinks  that  many  emotional  organic 
disturbances  are  morbid  and  useless  reactions.  He  says: 
"We  have  seen  that  the  graver  the  peril  becomes,  the  more 
do  the  reactions  which  are  positively  harmful  to  the  animal 
prevail  in  number  and  in  efficacy.  .  .  .  Their  extreme  degree 
is  indicated  by  morbid  phenomena  which  show  an  imperfec- 
tion in  the  organism.  We  might  almost  say  that  Nature  had 
not  been  able  to  frame  a  substance  which  should  be  excitable 
enough  to  compose  the  brain  and  spinal  marrow,  and  yet 
which  should  not  be  so  excited  by  exceptional  stimulation  as 
to  overstep  in  its  reactions  those  physiological  bounds  which 
are  useful  to  the  conservation  of  the  creature."  l 

Recent  physiological  researches  have,  however,  shown 
that  some  of  these  emotional  organic  disturbances  in  ques- 
tion do  serve  the  organism  in  emotional  crises.  It  has  been 
shown,  for  instance,  that  when  a  cat  is  frightened  or  angered 
by  the  barking  of  a  dog  certain  glands  attached  to  the  kid- 
neys immediately  begin  to  secrete  a  substance  known  as 
adrenalin.  The  adrenalin  is  thrown  into  the  blood  and 
causes  the  blood  vessels  in  the  abdominal  organs  to  contract 
and  those  in  the  legs,  lungs,  heart,  and  brain  to  dilate.  The 
blood  is  thus  forced  into  the  muscles  which  are  needed  for 
escape  or  attack,  and  the  heart,  lungs,  and  brain  are  prepared 
for  the  extraordinary  effort  needed  to  adjust  the  animal  to 
the  new  situation.  The  barking  of  the  dog  awakens  in  the 
cat  impulses  of  attack  or  flight,  which  in  turn  stimulate  the 
action  of  the  adrenal  gland.  The  emotional  seizure  thus 
serves  a  definite  purpose.  Other  emotions  may  have  similar 
stimulating  effects  on  the  different  glands  of  the  body  by 
virtue  of  which  the  organism  is  better  prepared  for  needed 
adjustments. 

According  to  Darwin  all  emotional  reactions,  or  expres- 
sions, are  due  either  (i)  to  survivals  of  once-useful  acts,  or 
(2)  tfL  movements  antithetic  to  those  acts,  or  (3)  to  move- 
1  "La  Paura,"  Appendice,  p.  295.  • 


388  PSYCHOLOGY 

ments  resulting  from  excess  nervous  discharge  or  overflow. 
The  first  principle  we  have  discussed.  The  principle  of  anti- 
thetic movement  is  stated  by  Darwin  as  follows:  Certain 
mental  states  lead  to  certain  forms  of  actions  which  are  of 
service  to  the  organism.  When  a  directly  opposite  state  is 
induced  there  is  a  strong  involuntary  tendency  to  the  per- 
formance of  movements  of  a  directly  opposite  nature,  al- 
though they  are  of  no  use.  In  some  cases  these  movements 
are  highly  expressive.1  Darwin  explains  the  expressions  of 
the  feeling  of  impotence  by  this  principle.  The  feeling  of 
power  which  is  present  in  the  emotion  of  rage  leads  to  the 
expression  of  lowered  eyebrows,  raised  shoulders,  and  clenched 
fists.  Now  the  feeling  of  impotence  is  a  mental  'state  di- 
rectly opposed  to  the  feeling  of  power.  Accordingly,  it  mani- 
fests a  tendency  to  movements  of  an  opposite  nature,  which 
are  raised  eyebrows,  lowered  shoulders,  and  open  palms. 
This  principle  of  antithesis  has  not  been  very  widely  accepted 
by  critics.  The  third  principle — that  of  excess  nervous  dis- 
charge or  overflow — we  have  accepted  as  the  neural  condition 
accompanying  the  impeded  conscious  activities  which  form 
the  psychical. basis  of  emotion. 

In  emotions,  then,  we  are  aware  more  or  less  vaguely  of 
a  mass  of  organic  reactions  and  bodily  movements.  Instead 
of  our  having  an  emotion  first  and  acquiring  its  so-called  ex- 
pressions later,  it  turns  out  that  certain  useful  instinctive 
reactions  acquired  in  the  struggle  for  "existence,  and  certain 
movements  due  simply  to  excess  nervous  discharge  have  left 
after-effects  within  us  which  are  conditioning  factors  in  emo- 
tional seizures.  It  is,  therefore,  not  correct  to  think  of  these 
bodily  reactions  merely  as  expressions  of  emotions.  Their 
function  was  not  to  express  emotions,  but  rather  to  respond 
/  in  an  adaptive  way  to  the  situations  which  start  the  bodily 
^  reactions.  To  an  external  observer  these  reactions  may  be 
signs  of  the  presence  of  certain  emotions,  but  from  the  point 

'Taken  with  verbal  changes  from  "The  Expressions  of  Emotions  in  Man 
and  Animals." 


TV 


EMOTIONS  389 

of  view  of  the  person  who  is  experiencing  the  emotion  they 
are  not  expressions.  Whenever  we  speak  of  these  reactions 
as  expressions  of  emotions  we  mean  only  that  they  are  symp- 
tomatic of  emotional  states. 

Among  the  bodily  reactions  characteristic  of  emotion  are 
the  facial  expressions  which  seem  to  form  a  class  by  them- 
selves. Thus,  we  look  disappointed,  hurt,  or  pleased;  we 
smile,  shed  tears,  or  turn  up  the  nose.  These  so-called  emo- 
tional expressions  call  for  consideration  because  they  do  not 
at  first  glance  seem  to  come  under  the  principle  of  utility. 
Of  what  use  to  the  organism  was  the  reaction  of  smiling,  or 
shedding  tears?  Thorndike1  asserts  that  they  are  useful  re- 
actions in  that  they  make  a  difference  in  the  behavior  of  other 
men  toward  us.  Any  woman  knows  the  utility  of  tears  in1 
this  respect,  and  has  instinctively  made  effective  use  of  them 
from  the  very  beginning.  Wundt2  proposes  another  explana- 
tion. He  thinks  that  the  facial  expressions  of  emotions  cor- 
respond to  definite  reflex  and  adaptive  adjustments  made  in 
response  to  stimuli  affecting  the  facial  sense-organs,  especially 
those  of  taste  arid  smell.  Thus  the  emotional  expressions  of 
the  mouth  resemble  the  reflexes  set  up  by  the  taste-stimuli 
of  sour,  bitter,  and  sweet.  When  a  man  looks  "sour"  or 
"bitter"  in  disappointment,  or  anger,  his  mouth  makes  the 
same  movements  and  assumes  the  same  positions  that  it 
does  in  actually  tasting  sour  and  bitter  substances.  "Sour 
and  bitter  looks  depend  upon  reflex  movements  which  serve 
to  prevent  the  contact  of  certain  ill-tasting  substances  with 
the  portions  of  the  tongue  most  sensitive  to  them."  Like- 
wise when  the  maiden  looks  sweet  and  smiling  the  facial  ex- 
pression is  similar  to  that  in  actually  tasting  a  sweet  sub- 
stance. Since  the  tip  of  the  tongue  is  most  sensitive  to 
sweet,  the  movements  consist  in  drawing  back  the  lips  about 
the  tip  of  the  tongue  in  order  to  bring  it  "in  as  complete 
contact  as  possible  with  the  sweet  substance." 

1  "Educational  Psychology,"  vol.  I,  p.  158. 

2  "Human  and  Animal  Psychology,"  Lecture  XXVI. 


390  PSYCHOLOGY 

Now,  the  taste  of  sour  and  bitter  and  sweet  are  connected 
with  the  affective  states  of  pleasantness  and  unpleasantness. 
It  seems  probable  that  other  cognitive  experiences  having 
similar  affective  states  should  become  associated  with  these 
facial  senses,  especially  in  the  primitive  stages  of  life.  Un- 
pleasant experiences  of  any  kind  would  naturally  remind 
primitive  man  of  these  gustatory  sensations  connected  with 
food-getting,  and  their  arousal  would  initiate  their  motor 
reflexes  and  so  give  rise  to  sour  and  bitter  looks.  Likewise 
pleasant  experiences  would  make  him  look  sweet  and  smiling. 
In  time  the  gustatory  terms  would  drop  out  so  that  the  con- 
nection between  unpleasant  experiences  and  sour  and  bitter 
looks  and  between  pleasant  experiences  and  sweet  looks 
would  become  a  direct  one.  If  this  is  true  it  seems  necessary 
to  assume  a  neural  connection  in  the  central  nervous  system 
between  other  centres  than  the  gustatory  centre  and  the 
muscles  of  facial  expression.  Observation  of  the  facial  con- 
tortions of  any  new-born  baby  seems  to  lend  support  to  this 
hypothesis. 

The  result  is  that  "analogous  feelings"  tend  to  copy  or 
imitate  already  established  responses  to  stimuli.  This  prin- 
ciple explains  why  in  moral  disgust  we  raise  the  nostrils  and 
turn  the  head  away,  just  as  we  do  when  actually  experienc- 
ing a  nauseous  odor.  We  must,  of  course,  allow  for  a  cer- 
tain amount  of  variation  and  modification  in  these  mimetic 
movements.  They  may  become,  as  emotional  expressions, 
more  or  less  modified  or  changed  from  their  original  form. 
It  is  interesting  to  note  that  these  borrowed  reactions  now 
seem  perfectly  appropriate  to  the  emotions  in  which  they 
appear. 

The  fact  that  mimetic  movements  are  present  in  the  new- 
born child  raises  a  question  in  heredity  and  evolution.  This 
explanation  of  emotional  facial  expressions  seems  a  plausible 
one  for  the  individual,  but  if  the  expressions  are  original  in 
the  new-born  child  the  associative  connections  formed  in 
primitive  experiences  must  have  been  fixed  in  heredity.  Since 


EMOTIONS  391 

the  associations  themselves  cannot  be  transmitted  from  one 
generation  to  another,  the  neural  mechanism  of  the  associa- 
tion must  be.  If  the  young  child,  long  before  he  has  had 
any  extended  experience  in  gustatory  sensations,  manifests 
the  emotional  facial  expressions  during  his  affective  states, 
then  he  must  have  inherited  the  neural  connections  whereby 
central  stimulation,  as  well  as  gustatory  stimulation,  can 
occasion  the  mimetic  responses.  We  cannot  go  further  into 
this  question  here  because  it  involves  certain  fundamental 
biological  problems  concerning  heredity  which  have  not  yet 
been  settled. 

Conditions  Which  Give  Rise  to  Emotions. — Since  emo- 
tions are  characterized  by  the  bodily  resonance  resulting  from 
instinctive  impulses  which  exhaust  themselves  within  the 
organism  itself,  our  next  task  will  be  to  find  out  under  just 
what  conditions  these  bodily  affecting  reflexes  are  called  into 
being.  Why  do  certain  objects  or  events  excite  the  bodily 
affecting  impulses  instead  of  the  motor  co-ordinations  which 
deal  directly  and  efficiently  with  external  objects  ?  We  shall 
find  in  examining  a  series  of  typical  emotions  that  they  are 
initiated  by  the  perception  or  ideation  of  objects  or  events 
which  obstruct  our  conscious  plans  and  purposes,  and  inhibit 
the  adaptive  voluntary  and  involuntary  co-ordinations  which 
serve  to  carry  them  out.  Zeno  the  Stoic  said  that  "emo- 
tion is  a  movement  in  opposition  to  the  soul."  In  all  emo- 
tional seizures  there  is  a  sudden  interruption  of  conscious 
action  and  a  consequent  checking  of  voluntary  control  be- 
cause of  the  presentation  of  certain  stimuli  to  which  the 
organism  does  not  consciously  adjust  itself.  In  all  cases  of 
blocked  conscious  control  there  are  two  possible  results. 
Either  the  nervous  excitation,  set  up  in  the  brain  centres  by 
the  stimuli,  may  drain  off  into  co-ordinated  and  smoothly 
running  instincts  and  habits  which  are  effective  in  dealing 
with  the  situation,  or  it  may  be  turned  back  and  diffused 
into  organic  and  motor  channels  and  there  arouse  a  mass  of 
conflicting  organic  and  motor  impulses.  It  is  the  latter 


3Q2  PSYCHOLOGY 

^alternative  which  furnishes  the  condition  for  emotion.  We 
have  already  noted  that  in  such  cases  part  of  the  nervous 
overflow  follows  old  hereditary  pathways  leading  to  once  use- 
ful reflexes.  It  is  also  true  that  part  of  the  nervous  excita- 
tion may  escape  into  ineffective  habitual  and  voluntary 
pathways,  i.  e.,  ineffective  so  far  as  the  present  stimulus  is 
concerned.  The  essential  condition  for  emotion,  however,  is 
that  conflicting  motor  tendencies  are  aroused,  and  that  these 
tendencies  are  initiated  by  the  appearance  of  conscious  states 
which  suddenly  block  conscious  activity  and  interrupt  the 
continuity  of  our  plans  and  purposes.  In  so  far  as  con- 
sciously directed  activity  or  instinctive  behavior  does  not 
lead  to  conflicting  impulses,  but  runs  out  into  single  and 
consistent  lines  of  adaptive  movements,  the  condition  for 
emotion  is  not  present.  We  may  see  this  principle  illustrated 
in  any  one  of  the  clear-cut  emotions.  For  example,  a  trav- 
eller in  the  north  woods  becomes  aware  that  a  pack  of  hun- 
gry wolves  is  close  upon  his  heels.  The  perception  of  this 
fact  suddenly  breaks  in  upon  his  consciousness  and  intrudes 
itself  as  a  barrier  to  the  purposes  dominating  his  mind  at  the 
time.  He  sees  himself  torn  to  pieces  by  the  hungry  beasts, 
and  all  his  plans  frustrated.  His  mental  faculties  are  para- 
lyzed. He  cannot  think  himself  out  of  the  difficulty.  The 
nervous  excitement  started  by  the  sound  of  the  oncoming 
pack  is  discharging  into  organic  and  motor  pathways.  He 
turns  pale,  trembles,  and  feels  a  sickening  sensation  in  his 
stomach.  His  mouth  becomes  dry  and  beads  of  perspiration 
stand  out  on  his  forehead.  He  is  torn  by  conflicting  im- 
pulses to  cry  out,  to  run,  to  hide,  to  stand  still,  to  crouch 
down,  to  defend  himself,  etc.  Just  as  long  as  our  traveller 
is  unable  to  shut  out  the  disturbing  and  interrupting  con- 
scious states  which  are  initiated  by  the  threatening  stimulus, 
and  fails,  therefore,  to  get  control  of  consciousness,  he  is 
swept  by  paroxysms  of  fear.  On  the  other  hand,  the  mo- 
ment he  is  able  to  think  of  some  way  out  of  his  dilemma — if 
he  happens  to  remember  that  on  the  trail  just  ahead,  under 


EMOTIONS  393 

a  clump  of  trees,  is  a  log  cabin  which  will  furnish  a  means 
of  escape  from  danger,  the  obstructing  conscious  states  are 
crowded  out.  The  onward  flow  of  his  mental  processes  will 
be  resumed  and  all  his  nervous  energy  will  drain  off  into  the 
single  adaptive  reaction  of  running.  So  long  as  no  doubt  of 
his  ability  to  reach  the  cabin  in  time  enters  his  mind  there 
will  be  no  conflicting  impulses  within  and  the  emotion  will 
die  down.  In  this  case,  the  perception  of  the  wolves  is  not 
an  obstruction  to  the  conscious  purposes  which  the  traveller 
has  in  view.  The  perception  of  the  wolves  takes  its  place  in 
his  consciousness  without  interrupting  its  progress  toward 
the  desired  end.  The  chances  are,  however,  that  the  trav- 
eller will  be  unable  to  keep  his  thoughts  fixed  upon  the  single 
purpose  and  the  movements  necessary  to  carry  it  out.  Each 
fresh  outburst  of  the  howling  beasts  behind  will  tend  to  dis- 
tract his  mind  and  set  up  conflicting  impulses  to  look  back 
to  see  if  the  pursuing  animals  are  gaining  upon  him,  to  stop 
and  defend  himself,  to  hide,  or  climb  a  tree.  The  organic 
overflow  of  nervous  excitement  again  takes  place  and  recur- 
rent waves  of  fear  seize  him.  Not  until  the  antagonism  of 
mental  states  and  the  conflict  and  inhibition  of  impulses  has 
ceased  will  he  be  freed  from  his  terror.1 

The  emotion  of  joy  manifests  entirely  different  sets  of 
antagonistic  conscious  states  and  conflicting  impulses,  but 
the  same  conditions  of  obstructed  conscious  flow  and  conse- 
quent diffusion  of  nervous  excitation  are  found  here  as  in 
other  emotions.  The  telegram  announcing  the  final  success 
of  some  enterprise  for  which  we  have  been  eagerly  striving 
suddenly  puts  a  barrier  across  the  line  of  our  thoughts.  For 
the  moment  we  are  dazed.  The  mental  processes  do  not  go 
on  in  the  same  uninterrupted  way.  We  cannot  instantly 
adjust  ourselves  to  the  new  situation.  We  are  seized  with 
impulses  to  jump  and  dance,  to  shout,  and  laugh,  to  thump 
or  hug  the  person  nearest  at  hand,  or  even  to  cry  with  tears 
of  joy.  Previous  thoughts  of  doubt  and  failure  are  revived 

1  See  also  Angell's  description  of  fear,  "Psychology,"  p.  375. 


394  PSYCHOLOGY 

and  overcome  by  the  present  knowledge  of  success.  The 
emotion  rises  in  proportion  as  we  become  aware  of  the  ten- 
sion and  stress  between  the  impulses  coming  from  the  antago- 
nistic and  oscillating  thoughts.  Not  until  the  mental  cyclone 
has  passed  do  we  get  possession  of  our  senses  and  act  in  a 
sane  and  sensible  manner.  And  so  we  might  go  through  the 
list  of  emotions  only  to  find  in  each  case  the  same  condition 
of  conscious  interruption  and  conflict.  Some  emotions  mani- 
fest this  condition  more  markedly  than  others.  As  it  mani- 
fests itself  less  and  less  the  emotions  shade  off  into  simple 
feelings. 

The  different  qualities  which  emotions  show  are  deter- 
mined by  the  nature  of  the  organic  and  muscular  responses 
aroused  by  the  various  emotional  objects  and  events.  We 
have  already  found  that  many  of  these  different  organic  re- 
sponses are  in  turn  determined  by  hereditary  influences  which 
reach  far  back  in  organic  development.  They  are  the  rem- 
nants of  adaptive  reactions  which  now  play  upon  the  organ- 
ism and  re-echo  earlier  struggles  for  existence.  But  we  must 
not  forget  that  these  reactions  are  set  off  by  the  overflow  and 
diffusion  of  nervous  excitement  accompanying  interrupted  or 
blocked  conscious  processes. 

Significance  of  Emotions. — Emotional  seizures  appear  in 
situations  where  new  adjustments  of  consciousness  are  needed 
in  order  to  go  forward  efficiently.  They  are  signs  that  the 
organism  has  need  of  more  than  the  usual  supply  of  nervous 
energy  to  meet  the  situation  presented.  The  temporary  agi- 
tation and  bodily  disturbance  may  therefore  be  looked  upon 
as  a  means  of  preparing  the  organism  for  extraordinary 
effort.  The  diffused  excitement  starts  the  machinery  going 
along  many  lines  of  bodily  activities,  and  thus  serves  as  a 
kind  of  general  preparation.  It  may  seem  at  first  thought 
that  we  shall  have  difficulty  in  applying  this  principle  to  the 
depressing  effect  of  an  emotion  like  that  of  grief.  But  we 
must  remember  that  situations  which  occasion  the  depress- 
ing emotions  do  not  call  for  vigorous  action  to  meet  them 


EMOTIONS  395 

properly.  On  the  other  hand,  they  demand  quiet  and  repose 
before  we  can  become  adjusted  to  them.  The  emotion  in 
these  cases  furnishes  an  outlet  for  the  excitement  caused  by 
the  disturbing  facts.  Sorrowful  situations  are  for  the  most 
part  events  that  have  already  taken  place,  and  nothing  that 
we  can  do  will  change  them.  The  situation  requires  then 
simply  a  rational  and  philosophic  attitude  on  our  part. 

Classification  of  the  Emotions. — Since  emotions  are  highly 
complex  mental  states  into  which  many  different  conscious 
elements  may  enter,  it  is  to  be  expected  that  psychologists 
will  group  them  in  all  sorts  of  ways,  accordingly  as  they  em- 
phasize this  or  that  factor.  Emotions  may  be  classified  upon 
the  basis  of  their  predominant  and  primary  affective  states 
as  pleasant  and  unpleasant  emotions;  or  according  to  the  in- 
tensity of  these  affective  states  as  weak  or  strong  emotions; 
or  according  to  the  character  of  their  bodily  reactions  as 
stfenitjOT  asthenic  emotions;  or  according  to  the  form  of  their 
occurrence  as  slowly  arising  or  suddenly  arising  emotions; 
or  according  to  the  external  situations  which  occasion  them 
as  food  emotions,  sex  emotions,  etc. ;  as  egoistic  or  non-egoistic 
emotions;  as  sensuous  or  intellectual  emotions;  as  subjective 
or  objective  emotions,  and  many  more.  Some  of  these  classi- 
fications are  purely  psychological  and  some  psychophysical. 
Wundt  has  proposed  a  very  elaborate  classification  based 
upon  psychological  differences  only.1  Bain's  classification  of 
the  emotions  found  in  the  Appendix  of  his  "Emotions  and 
the  Will"  is  worthy  of  note. 

Emotions  and  Memory. — We  have  already  spoken  of  the 
fact  that  feelings  are  not  likely  to  be  recalled,  but  are  created 
anew  when  our  cognitive  experiences  are  recalled.  As  we 
should  expect,  our  emotions,  too,  are  not  subject  to  recall. 
We  can  remember  that  we  were  angry  or  sorrowful,  but  we 
do  not  image  the  emotions  themselves.  When  we  think  of  a 
past  insult  the  anger  which  arises  is  a  new  anger,  not  the  old 
anger  that  we  experienced  at  the  time  the  actual  insult  was 

1  "Outlines  of  Psychology,"  English  translation,  p.  198,  paragraph  13. 


396  PSYCHOLOGY 

received.  The  more  vividly  we  image  the  circumstance  the 
more  likely  we  are  to  experience  anger  when  thinking  about 
it.  The  thought  causes  the  same  impeded  consciousness  and 
the  same  or  similar  organic  diffusion  and  conflicting  motor 
impulses  and  the  emotion  becomes  actual,  not  recalled. 
Shame  and  anger  are  especially  liable  to  be  recreated  by  the 
memory  of  the  original  events  which  occasioned  them.  We 
blush  with  shame  when  thinking  of  some  recent  folly  of  ours. 
We  set  our  teeth  in  anger  when  we  recall  some  personal 
affront. 

Time,  however,  lessens  the  intensity  of  these  repeated 
emotions,  or  even  leaves  us  cold  and  without  emotional 
warmth.  Events,  which  at  first  stir  our  very  being  when  we 
think  of  them,  come  in  time  to  be  recalled  with  no  emotion 
whatever,  although  the  events  themselves  are  remembered  as 
vividly  as  before.  This  means  that  these  memories  become 
rationalized  and  harmonized  into  our  conscious  life,  so  that 
they  cease  to  be  obstructing  conscious  factors.  If  this  were 
not  so,  we  should  be  so  beset  by  disturbing  emotions  that 
clear  thought  and  efficient  behavior  would  be  impossible. 
The  nervous  energy  which  is  at  first  set  free  in  emotional 
excitement  becomes  available,  through  this  process  of  accom- 
modation, for  rational  control.  This  subduing  effect  of  time 
makes  the  difference  between  the  hot-headed  and  impetuous 
youth  and  the  mature  and  experienced  man  of  the  world. 


CONSCIOUSNESS  AND   BEHAVIOR 

From  its  very  first  appearance  in  the  life  process,  con- 
sciousness has  been  connected  with  the  motor  responses.  In 
fact  its  fundamental  function  has  been  to  guide  behavior. 
But  the  individual  begins  his  career  with  a  group  of  native 
reactions  which  are  not  consciously  controlled  or  directed. 
These  native  forms  of  behavior  are  the  purely  physiological 
reactions,  the  reflexes,  and  the  instincts.  They  are  present 
prior  to  experience  on  the  part  of  the  individual,  and  although 
they  are  not  controlled  by  him  they  nevertheless  serve  to 
adjust  him  to  his  first  surroundings.  These  native  reactions 
serve  as  a  foundation  upon  which  the  individual  builds  up 
his  acquired  forms  of  behavior  which  are  necessary  for  his 
continued  existence. 

The  native  reflexes  and  instincts  represent  the  individual's 
hereditary  endowment  in  the  way  of  behavior,  while  the  ac- 
quired reactions  represent  what  he  gains  for  himself  through 
the  aid  of  consciousness.  After  the  first  stages  of  develop- 
ment both  native  and  acquired  reactions  are  present.  As 
development  proceeds  the  acquired  reactions  increase  in 
number  and  complexity  and  the  native  reactions  are  modified 
by  experience.  The  behavior  of  the  organism  becomes, 
therefore,  a  varying  mixture  of  native  and  acquired  reactions 
— sometimes  largely  native,  sometimes  largely  acquired  reac- 
tions, depending  upon  whether  the  conscious  experience  of 
the  organism  plays  a  small  or  large  part  in  determining  its 
behavior. 

So  far  we  have  spoken  only  of  the  co-ordinated  reactions 
of  the  organism.  Over  and  above  these  reactions  the  organ- 
ism manifests  a  group  of  unco-ordinated  and  diffuse  move- 

397 


398  PSYCHOLOGY 

ments  which  are  usually  spoken  of  as  random  movements. 
While  these  movements  are  the  result  of  stimulation,  they 
are  not  directed  to  any  particular  end.  They  are  the  out- 
come of  diffuse  nervous  energy  flowing  into  the  muscles  of 
the  body. 

To  complete  our  list  of  bodily  reactions,  or  behavior,  we 
must  add  the  important  group  of  volitional  reactions.  Voli- 
tional reactions  are  the  acts  which  are  immediately  deter- 
mined and  controlled  by  consciousness. 

Summing  up  the  forms  of  behavior  we  have: 

1.  Purely  physiological  reactions. 

2.  Unco-ordinated  random  reactions. 

3.  Native  reflexes. 

4.  Instincts. 

5.  Acquired  reflexes. 

6.  Habits. 

7.  Ideo-motor  reactions. 

8.  Volitional  reactions. 

The  physiological  reactions  are  those  in  which  conscious- 
ness plays  the  least  part.  They  are  usually  considered  as 
unconscious  reactions.1  They  are  the  reactions  involved  in 
respiration,  circulation,  intestinal  processes,  glandular  secre- 
tions, pupilary  reflexes,  etc. 

The  unco-ordinated  random  reactions  are  the  diffuse  move- 
ments which  have  no  definite  end.  A  brightly  colored  object 
may  stimulate  the  young  infant  to  make  many  random  move- 
ments in  the  different  parts  of  the  body.  Head,  face,  arms, 
legs,  and  feet  may  all  move  about  in  an  aimless  way  when 
he  catches  sight  of  the  object.  Since  the  child  has  inherited 
no  definite,  preformed  neural  pathway  for  carrying  off  all 

1  The  purely  physiological  reactions  are  not  absolutely  divorced  from  con- 
sciousness. It  is  a  demonstrated  fact  that  mental  states  may  influence  or 
even  initiate  these  physiological  activities.  The  perception  of  food  may  start 
the  secretion  of  saliva.  The  presence  in  the  mind  of  certain  ideas  may  affect 
circulation  and  respiration — the  bated  breath,  the  blush  of  shame,  the  pallor 
of  fear,  the  flush  of  anger,  all  testify  to  the  effect  of  consciousness  upon  the 
purely  physiological  activities, 


CONSCIOUSNESS  AND   BEHAVIOR  399 

nervous  excitement,  it  is  diffused  into  various  pathways  lead- 
ing to  a  large  number  of  muscles.  This  diffused  activity  has 
been  called  "excess  reaction"  or  "multiple  response  to  a 
single  stimulus." 

The  native  reflexes  are  the  simplest  and  most  direct  co- 
ordinated movements.  They  are  made  in  response  to  sensory 
stimuli.  The  closing  of  the  baby's  hand  when  the  palm 
is  stimulated  and  the  sucking  movements  following  tactual 
stimulation  of  his  lips  are  common  illustrations  of  the  native 
reflexes. 

The  instincts  are  complex  native  reactions  composed  of  a 
number  of  native  reflexes  chained  together  in  such  a  way 
that  they  lead  to  an  adjustment  of  the  organism  as  a  whole 
to  some  outer  situation.  Sometimes  the  term  instinct  is  used 
to  signify  all  the  native  reactions  from  the  purely  physio- 
logical reactions  to  the  most  complex  native  reactions.  We 
shall  use  the  term  to  signify  only  the  complex  chained  reac- 
tions leading  to  a  single  end.  Instincts  are  inherited  forms 
of  reaction  and  are,  therefore,  the  result  of  the  transmission 
from  parent  to  offspring  of  preformed  neural  pathways. 
While  instinct  is  not  consciously  controlled  by  the  individ- 
ual, it  is  nevertheless  attended  by  an  impelling  consciousness, 
craving  or  appetent  in  quality.  Illustrations  of  instincts  are 
found  in  the  reactions  of  fear,  anger,  jealousy,  rivalry,  ac- 
quisitiveness, parental  love,  play,  and  imitation.  In  man 
instincts  are  rarely  pure,  for  they  are  modified  by  experience 
and  supplemented  by  volitional  and  acquired  activities. 

The  following  reactions  are  all  acquired,  and  differ  from 
the  preceding  forms  of  motor  activity  in  that  they  are  learned 
during  the  lifetime  of  the  individual  as  the  result  of  his  own 
experience. 

The  acquired  reflex  is  the  simplest  acquired  response.  Ac- 
quired reflexes  are  the  elementary  reactions  out  of  which 
habits  are  formed.  These  reflexes  are  direct  responses  to 
sensory  stimulation.  Illustrations  of  acquired  reflexes  are 
found  in  the  simple  movements  of  skill  which  when  chained 


400  PSYCHOLOGY 

together  constitute  ability  in  playing  tennis,  performance  on 
the  piano,  etc. 

Habit  bears  very  much  the  same  relation  to  acquired  re- 
flexes that  instinct  bears  to  the  simple  native  reflexes.  Habit 
is  a  complex  act  composed  of  a  number  of  simple  reflexes 
chained  together  and  so  co-ordinated  that  they  result  in 
movements  toward  a  definite  end.  Habit  is  like  instinct  in 
that  it  is  a  relatively  fixed  form  of  reaction,  depending  upon 
the  existence  of  neural  pathways  and  going  on  without  the 
control  of  consciousness.  It  is  unlike  instinct  in  that  it  is  a 
form  of  behavior  which  has  been  learned  by  the  individual, 
\  acquired  by  virtue  of  his  own  experience.  It  is  individual 
\rather  than  racial  in  its  origin.  Movements  which  are  often 
{repeated  under  conscious  direction  become  habits.  The  piano- 
"player  at  first  must  consciously  direct  each  single  movement 
of  his  fingers,  but  after  many  repetitions  the  movements  be- 
come so  closely  associated  together  that  they  may  go  on 
without  conscious  control.  According  to  the  "law  of  habit" 
motor  reactions  once  made  make  it  easier  for  the  same  reac- 
tions to  occur  again.  This  is  due  to  some  form  of  neural 
modification  left  in  the  nerve  pathways  of  the  brain  by  past 
experience.  The  nervous  material  is  sufficiently  plastic  to  be 
modified  by  repeated  neural  activity,  and  yet  sufficiently 
stable  to  retain  the  modifications. 

Habit  involves  the  perception,  or  image,  or  thought  of 
ome  object  or  situation  which  has  in  the  past  been  associated 
with  the  motor  activities  making  up  the  habit  and,  in  addi- 
tion, the  consciousness  of  the  sensations  arising  from  the 
simple  movements  as  they  take  place.  Each  sensation  is  the 
cue  for  the  next  movement,  which  in  turn  gives  another  sen- 
sation, serving  in  its  turn  as  the  cue  to  another  movement, 
and  so  on  until  the  series  of  movements  and  sensations  are 
run  off.  Tliis  sensory-motor  process  takes  place  within  snrpe 

^  conscious  purpose  or  plan.  The  plan  or  purpose  doesr  not, 
hoffi£veri  include  the  conscious  control  of  the  single  move- 
ments. The  part  which  kinassthetic  sensations  play  in  habit 


CONSCIOUSNESS  AND   BEHAVIOR  401 

is  made  evident  by  the  fact  that  if  they  are  absent  habit  is 
seriously  interfered  with.  For  instance,  in  locomotor  ataxia 
the  patient  is,  by  reason  of  a  diseased  condition  of  the  spinal 
cord,  insensible  to  the  sensations  of  movement  in  the  lower 
extremities.  For  this  reason  locomotion  becomes  very  im- 
perfect and  in  some  cases  impossible.  By  means  of  certain 
drugs  sensations  of  movement  in  the  hand  and  arm  may  be 
lessened  or  abolished  for  a  time.  This  temporary  anaesthesia 
makes  it  extremely  difficult  for  the  hands  to  perform  any  of 
their  accustomed  acts  or  habits. 

Ideo-motor  reactions  differ  from  the  reflexes  in  being  a  re- 
sponse to  an  image  or  thought  instead  of  a  response  to  a 
sense  presentation.  The  image  of  an  act  or  of  the  result  of 
an  act  may  be  followed  immediately  by  the  act  which  takes 
place  without  conscious  intention.  The  act  is  then  said  to 
be  ideo-motor. 

Volitional  Action. — The  discussion  of  volitional  action 
should  have  introduced  the  description  of  all  the  acquired 
reactions — acquired  reflexes,  ideo-motor  activities,  and  habit. 
For  these  are  best  understood  in  the  light  of  volitional  activi- 
ties. Most  of  our  acquired  reactions  were  originally  voli- 
tional reactions.  Before  they  became  fixed  as  habitual  forms 
of  action  they  required  the  constant  control  of  consciousness. 
Volitional  action  is  therefore  a  transitional  stage  of  activity. 
It  is  really  not  acquired  action,  but  action  in  the  stage  of 
being  acquired.  From  the  point  of  view  of  consciousness  it 
is  the  standard  form  of  activity.  All  acquired  forms  drop 
away  from  it  as  they  require  less  and  less  consciousness  in 
their  control.  Volitional  reaction  always  involves  full  con- 
sciousness of  the  action.  We  know  exactly  what  we  are 

•i  i  ii*"        i   ~      H   "~       _    n*~       |H         *^ 

goingtodobejorejffi^afit^  and  what  we  are  doing  while  me 
act  is  going  on.  Every  act  is  imaged  before  it  is  performed 
and  consciously  followed  during  its  performance.  In  addi- 
ction volitional  activities  involve  the  consciousness  of  the  end 
ot^  consequence  of  the  act. 

another  factor  must  be  considered  in  volitional  activ- 


<} 

jl 
p 


402  PSYCHOLOGY 

ity,1  and  that  is  the  consciousness  of  some  purpose  which  is 
accepted  or  consented  to,  and  within  which  the  image  of  the 
act  and  its  immediate  consequence  lie.  This  is  what  is 
meant  when  we  say  that  we  act  with  intention.  The  inten- 
tion or  purpose  may  include  in  its  simplest  form  only  the 
immediate  consequences  of  the  act,  or  it  may  include  the  far- 
reaching  consequences  of  some  life  plan.  For  instance,  I 
may  pick  up  the  pen  from  my  desk  simply  because  I  con- 
sciously desire  to  see  if  it  is  broken,  or  because  I  wish  to 
write  my  will.  However,  in  a  fully  conscious  or  volitional 
act,  purpose  or  intention  must  be  present.  The  conscious- 
ness which  presides  over  volitional  activities  is  impulsive,  as 
in  all  motor  consciousness.  But  it  differs  from  the  vague, 
impulsive  consciousness  accompanying  instinct  or  habit  in 
possessing  full  awareness  of  the  end,  awareness  of  the  move- 
ments necessary  to  accomplish  the  end,  and  the  conscious 
approval  of  the  end.  The  impulse  may  be  described  as  the 
expectant  attitude  toward  or  the  anticipation  of  some  definite 
end  represented  as  following  certain  movements.  The  idea 
of  the  movements  unblocks  the  outgoing  motor  pathways 
leading  to  the  muscles  involved  in  the  act.  Just  how  this 
unblocking  of  motor  pathways  in  the  brain  is  accomplished 
by  consciousness  we  do  not  know.  We  do  know  that  thought 
of  a  movement  tends  to  be  followed  by  the  movement,  and 
that  the  thought  of  an  end  tends  to  be  followed  by  the  move- 
ments  necessary  to  bring  about  the  end.  We  shall  discuss 
this  fact  more  thoroughly  later. 

Our   analysis  has   laid   bare  three  factors  in  volitional 
action: 

1.  Consciousness  of  the  act  to  be  performed. 

2.  Consciousness  of  the  end  or  consequences  of  the  act. 

3.  Consciousness  of  an  accepted  purpose  or  intention. 

1  Volitional  activity  is  usually  thought  of  as  including  any  form  of  activity 
following  conscious  intention  or  purpose,  whether  the  activity  itself  is  immedi- 
ately controlled  or  not.  In  this  sense  habitual  activities  may  be  termed  voli- 
tional activities.  But  volitional  activity  as  used  here  is  limited  to  those  activi- 
ties requiring  constant  conscious  control. 


CONSCIOUSNESS   AND   BEHAVIOR  403 

Consciousness  of  the  act  and  of  its  end  is  present  in  the 
form  of  images  just  before  the  act  is  executed.  These  images 
may  be:  (i)  Resident  images,  consisting  of  the  mental  images 
of  the  sensations  of  movement  (kinaesthetic  images)  needed 
in  the  act,  and  (2)  remote  images,  consisting  of  the  mental 
image  of  the  result  of  the  act  or  the  end  as  accomplished. 
For  instance,  if  I  image  the  sensations  in  the  throat  and  lips 
which  occur  in  the  pronunciation  of  the  word  "piper,"  we 
term  the  image  resident.  If,  on  the  other  hand,  I  image  the 
effect  of  the  act  (in  this  case  the  word  as  it  would  sound  when 
it  falls  upon  the  ear),  we  term  the  image  remote. 

Now  it  is  true,  as  some  psychologists  contend,  that  acts 
may  in  our  every-day  life  follow  upon  either  form  of  imagery 
or,  in  fact,  may  follow  any  mental  state  whatever,  provided 
the  act  has  been  in  the  past  associated  with  it.  The  mere 
sight  of  the  word  "piper"  on  a  printed  page  may  be  followed 
directly  by  the  act  of  its  pronunciation  without  any  imagery 
interposed  between  the  perception  and  the  act.  The  thought 
of  musical  instruments,  the  image  or  perception  of  a  rat,  the 
thought  of  children,  or  the  sound  of  the  word  Hamelin  may 
be  followed  immediately  by  the  pronunciation  of  the  word 
"piper."  But  in  any  one  of  these  cases  the  response  is  not 
a  "fully  conscious"  or  "volitional"  activity.  It  is  rath,ej  a* 
rform  of  acquired  activity  which  goesjon  withoutcpnscioijs| 
[direction  —  a  conscious  reflex  or  a  simple  haDlt-^Hepending  I 

C«S—  »  -----  -  -  ;-*.  -  .  ----  .  -----  ~--~^^—  _  _^*  -  -  -  ,«*  -  —  —  -  °| 

|upon  past__associations. 

A  volitional  act  may  be,  and  usually  is,  a  new  act  —  a  new 
adjustment—  or  a  new  combination  of  old  acts.     Now,  a  new,  t 
act   must   be_  consciously   imaged    and  _mnsfjnjis1y_ 


__ 

beforejt  can  be^p^ejf  ormeo^  It  has  no  past,  and  consequently 
there  are  no  associations  or  tendencies  established  which  will 
call  it  into  being.  As  volitional  action  is  repeated  again  and 
again,  the  controlling  consciousness  which  was  present  in  the 
beginning  drops  out  —  first  the  resident,  then  the  remote 
imagery,  and  even  the  intention  or  purpose,  until  any  con- 
scious state  which  has  been  associated  with  the  act  is  sufficient 


404  PSYCHOLOGY 

to  initiate  it.  It  then  becomes  an  acquired  activity.  This 
means  that  in  many  cases  the  first  stages  in  the  formation  of 
acquired  reactions  are  volitional.  When  consciousness  is 
able  to  take  note  of  the  native  reactions,  and  can  image  the 
sensations  involved  in  them,  it  has  adequate  material  for  voli- 
tional activity.  Volitional  activity,  then,  lies  between  the 
native  forms  of  behavior  and  the  acquired  forms — between 
what  the  organism  already  has  and  what  it  is  going  to  have. 
In  jhis  transformation  consciousness  plays  ^the  chief  role^ 

In  order  to  avoid  a  possible  confusion  we  should  note  the 
fact  that  we  may  exert  a  volitional  control  over  activities 
which  are  in  themselves  not  volitional.  For  instance,  voli- 
tional control  makes  use  of  acquired  reflexes  and  habits. 
Evidently  we  must  make  a  distinction  between  volitional  in 
the  larger  sense  and  volitional  activity  in  the  stricter  sense. 
I  may  will  to  write  a  letter  and  post  it  before  noon  to-day, 
but  the  actual  writing  and  posting  activities  are  all  well- 
formed  habits  and  may  need  little  conscious  control,  and  are, 
therefore,  in  themselves  not  volitional  acts.  Even  in  the 
stricter  sense,  volitional  activities  may  include  well-formed 
habits  within  the  total  activity.  While  consciousness  is  busy 
controlling  the  newer  parts  of  the  activity-complex,  the  habits 
within  it  run  themselves  off  subconsciously.  Much  of  human 
behavior  is  mixed,  partly  new  and  consciously  controlled  and 
partly  old,  and,  therefore,  needing  no  control.  The  higher 
and  newer  forms  of  behavior  are  constantly  incorporating 
and  making  use  of  the  lower  and  familiar  forms. 

While  this,  briefly,  is  the  history  of  the  formation  of 
many  of  our  acquired  reactions,  it  is  not  the  only  way  that 
they  are  developed.1  So  far  we  have  considered  only  those 
reactions  which  can  be  consciously  represented  before  they 
are  executed,  and  consequently  we  have  noted  only  those  ac- 
quired reactions  which  come  to  be  what  they  are  through  di- 
rect conscious  control.  This  conscious  control  of  movement 
is  the  highest  and  most  direct  method  of  learning  new  activi- 

1Hobhouse:  "Mind  in  Evolution,"  chap.  VIII. 


CONSCIOUSNESS   AND   BEHAVIOR  405 

ties.  It  is  probably  not  present  in  the  lower  animals,  for  it  is 
possible  only  where  conscious  representation  of  past  move- 
ments and  their  results  exists.  While  man  takes  advantage 
of  this  higher  type  of  learning,  he  exhibits  in  common  with 
the  animals  a  lower  and  more  primitive  method  of  building 
up  his  acquired  adaptive  responses1 — the  method  of  "trial- 
and-error"  or  the  "hit-and-miss"  type  of  learning. 

As  an  illustration  of  the  "  trial-and-error  "  method  we  may 
describe  briefly  one  of  Thorndike's  experiments  with  cats. 
He  prepared  a  box  whose  cover  and  front  side  had  been 
replaced  by  bars  an  inch  apart.  A  door  was  placed  in  the 
front,  and  so  arranged  that  it  would  open  when  a  wooden 
button  inside  was  turned  from  a  vertical  to  a  horizontal  posi- 
tion. A  very  hungry  cat  was  placed  inside  and  a  bit  of  fish 
just  outside.  The  stimulus  offered  by  the  odor  of  the  fish 
excited  the  cat  to  make  many  random  reflex  and  instinctive 
movements.  It  ran  about  clawing  and  biting  at  the  bars 
until,  after  a  long  time,  one  of  the  random  movements  hap- 
pened to  turn  the  button,  the  door  fell  open,  and  the  cat 
obtained  the  fish.  When  the  experience  had  been  repeated 
again  and  again  on  succeeding  days  the  cat  came  gradually 
to  omit  all  the  random  movements  but  those  of  clawing  and 
biting  the  button.  After  many  trials  it  learned,  therefore, 
to  open  the  box  immediately  by  pushing  the  button  with  its 
claws  or  nose.2  In  short,  it  had  acquired  a  co-ordinated  re- 
action on  the  basis  of  its  native  activity.  There  was  at  first 
a  mass  of  diffused  random  and  instinctive  movements  called 
out  by  the  stimulus.  Then  followed  the  gradual  elimination 
of  useless  and  unsuccessful  movements,  and  the  selection  of 
the  movements  necessary  to  meet  the  situation.  There  was 
no  conscious  representation  of  past  experience,  and  conse- 
quently no  conscious  control  or  volitional  activity.  The  first 
successful  movement  was  a  chance  reaction  present  in  the 
many  diffused  reactions.  The  final  acquirement  of  the  re- 

JRuger:  "Archives  of  Psychology,"  June,  1910. 
2Thorndike:  "Animal  Intelligence." 


406  PSYCHOLOGY 

sponse  came  only  after  many  repetitions  of  the  same  experi- 
ences. Of  all  the  movements  which  the  cat  made,  the  move- 
ment of  pushing  the  button  was  the  only  one  which  was  fol- 
lowed by  a  definite  result  giving  satisfaction.  The  movement 
thus  gradually  became  associated  with  the  box,  button,  and 
fish  situation.  It  was  subsequently  always  called  out  by 
that  situation.  If,  however,  in  such  cases  some  element  in 
the  situation  is  changed,  say  a  sliding  bolt  is  exchanged  for 
the  button,  the  animal  finds  itself  helpless,  and  must  go 
again  through  the  long  process  of  "trial  and  error"  in  order 
to  adjust  itself  to  the  new  condition.  The  part  which  con- 
sciousness plays  in  this  process  is  not  as  clear  as  in  the  case 
of  volitional  activity.  The  feelings  of  discomfort  before  the 
proper  adjustment  happens  to  be  hit  upon,  and  the  feeling  of 
satisfaction  when  it  is  found,  form  a  conscious  background 
for  the  right  movements  and  serve  to  emphasize  and  differ- 
entiate them.  Here  we  must  assume  a  native  tendency  in 
the  organism  to  avoid  reactions  which  bring  discomfort  and 
seek  those  which  bring  satisfaction. 

Young  children  manifest  very  markedly  this  type  of  learn- 
ing new  adaptive  responses.  Any  novel  stimulus  will  call 
out  a  mass  of  diffused  activity  containing  some  movements 
more  or  less  adaptive.  The  selection  of  the  right  movement 
goes  on  in  much  the  same  way  as  in  the  case  of  animal  learn- 
ing. The  selection  may  be  characterized  as  the  "survival  of 
the  fittest  responses."1  In  adults  the  method  of  "trial  and 
error"  is  especially  evident  in  acquiring  acts  of  skill.  It  is 
present  in  the  first  reactions  to  especially  novel  situations. 
But,  after  the  first  successful  response,  conscious  representa- 
tion and  control  appears  and  shortens  the  process.  In  the 
acquisition  of  skilled  movements,  however,  it  often  happens 
that  the  finer  adjustments  are  incapable  of  being  analyzed 

Iout  of  the  total  activity.     The  kinaesthetic  sensations  which 
these  movements  arouse  are  too  indistinct  to  be  differentiated 
from  each  other,  and  so  they  form  a  general  mass  of  sensa- 
1  Dexter,  Educational  Review,  vol.  XXXIII,  p.  81. 


CONSCIOUSNESS   AND   BEHAVIOR 


407 


tions.  In  this  case  the  movements  cannot  be  imaged,  and 
therefore  cannot  be  consciously  controlled.  The  only  method 
by  which  they  can  be  acquired,  then,  is  that  of  the  "hit-and- 
miss  "  type — try-try-again  method.  Continuous  and  patient 
practice  will  give  variations  in  the  nature  of  the  movements. 
Some  of  the  movements  will  fail,  and  some  of  them  will  just 
hit  the  mark  and  will  be  accompanied  by  the  feeling  of  satis- 
faction. Gradually  and  slowly  these  latter  movements  are 
"stamped  in"  and  all  others  eliminated  until  the  skilled  act 
is  acquired.  The  finer  adjustments  necessary  in  playing  ten 
nis,  billiards,  golf,  etc.,  the  skilled  touch  on  the  piano  or  vio 
lin,  and  the  exact  tension  of  the  vocal  chords  in  singing,  must 
all  be  acquired  slowly  by  the  hit-and-miss  method  of  learn 
ing.  This  is  so  because  we  are  unable  to  analyze  out,  anc 
consciously  represent,  the  extremely  fine  adjustments  neces- 
sary for  these  activities.  In  just  so  far,  however,  as  we  are 
able  to  sense  the  fine  differences  in  the  kinaesthetic  sensations 
of  skilled  movements,  and  are,  therefore,  able  to  represent 
mentally  the  movements,  we  can  consciously  control  them; 
but  when  the  differences  are  too  fine  to  be  sensed  we  are 
forced  to  rely  on  the  more  primitive  method  of  learning. 

Comparing  these  two  types  of  learning  new  adaptive 
responses,  we  find  that  the  chief  difference  between  them  lies 
in  the  method  employed  in  selecting  the  responses  that  are 
to  become  fixed  as  the  future  equipment  of  the  organism. 
The  stages  of  development  are  as  follows: 


Learning  through  trial  and  error : 

1.  Native  reactions. 

2.  Gradual   acquirement   of   suc- 

cessful reaction. 

3.  Acquired  reaction. 


Learning  through  conscious  repre- 
sentation : 
Native  reactions. 
Volitional  reaction. 

Acquired  reaction. 


In  the  method  of  trial  and  error  the  second  stage  appears 
to  be  a  form  of  natural  selection  in  which  the  units  of  selec- 
tion are  single  reactions  within  the  organism  instead  of  indi- 


408  PSYCHOLOGY 

vidual  organisms,  as  in  natural  selection  proper.  The  diffused 
random  actions  furnish  variations  from  which  selection  of 
the  fit  reaction  is  made.  According  to  the  theory  of  natural 
selection,  however,  no  account  is  taken  of  the  positive  agency 
of  consciousness  in  determining  what  organisms  are  to  be 
selected.  The  unfit  are  damped  out  by  the  environment;  the 
fit  survive.  On  the  other  hand,  in  learning  new  responses, 
even  by  the  trial-and-error  method,  the  organism  is  undoubt- 
edly aided  by  consciousness.  There  is  a  general  conscious 
tendency  toward  some  end.  This  tendency  drives  the  organ- 
ism to'  further  endeavor.  The  feelings  of  pleasure  accom- 
panying success  and  of  displeasure  attendant  upon  failure 
serve,  as  we  have  already  indicated,  to  stamp  in  the  success- 
ful reaction. 

In  the  higher  type  of  learning  new  responses  (learning 
through  conscious  representation),  the  method  of  selection 
makes  use  of  direct  conscious  representation  of  modes  of  past 
activity.  Images  ofprevious  movements  are  raised  to  the 
level  of  reflective  "omsciousness  and  "madejx)  jserve  as  a,  con- 
trolling agency!  Th^j^^e^po^is^Bie^taTEes^^ace^iinder^ 
conscious~coli  trounti  t  Hecmes'ed._  TKen  Consciousness 


tends  to  disappear. 

It  is  evident  that  consciousness  is  a  factor  in  learning  new 
responses.  It  is  not  needed  in  either  the  native  or  acquired 
reactions.  There  adjustments  take  place  with  automatic 
regularity.  But  where  the  native  and  the  acquired  adjust- 
ments are  inadequate,  there  is  need  of  a  directive  agency. 
In  such  cases  the  best  endeavor  of  the  organism  is  challenged 
and  it  responds  with  the  highest  power  it  possesses,  that  of 
consciousness.  Such  occasions  furnish  the  opportunity  for 
the  most  rapid  conscious  development.  In  fact,  without 
these  crises  in  the  life  of  the  organism  no  progress  is  possible. 
Unless  new  responses  are  constantly  in  process  of  acquire- 
ment, education  ceases.  So  the  greater  the  number  of  ad- 
justments required  in  the  life  of  an  organism,  the  higher  the 
stage  of  development  it  will  reach.  The  organism  that  is 


CONSCIOUSNESS  AND   BEHAVIOR  409 

perfectly  adjusted,  i.  e.,  has  all  the  native  and  acquired  re- ft 
sponses  needed  to  meet  its  requirements,  has  reached  the  end  H 
of  its  conscious  development.  Perfectly  formed  habits,  while  ' 
they  are  useful  in  maintaining  life  on  the  level  of  its  present 
attainment,  do  not  serve  to  raise  the  organism  to  a  higher 
level.  It  is  only  in  the  formation  of  habit  that  the,  process  of  L 
education  goes  on.  Practically  no  advance  comes  from  the 
habitual  modes  of  activities.  Man's  high  development  is 
due  to  the  fact  that  he  is  continually  forced  to  learn  new 
habits  of  action  in  order  to  adjust  himself  to  the  world  about 
,him.  He  never  becomes  fully  adjusted  because.  **.  VIP  rlq-  y 
velops,  his  environment  enlarges  and  changes,  and  conse-|i 
[quently  demands  new  responses. ..  This  requires  the  forma- 
tion of  a  large  number  of  habits  which  must  be  continually 
broken  up  and  reformed  under  the  direction  of  consciousness. 
It  is  where  his  habits  become  absolutely  fixed  that  he  ceases 
to  develop.  For  this  reason  long-continued  operation  of  an 
automatic  machine  reacts  deleteriously  upon  its  operator. 
The  man  who  works  eight  hours  a  day,  month  after  month, 
upon  such  a  machine  is  limited  in  his  activities  to  a  monoto- 
nous circle  of  habit  which  inhibits  mental  activity,  and  in  the 
end  lessens  the  plasticity  of  the  nervous  tissue,  and  therefore 
the  possibility  of  reactions  of  a  higher  order.  He  thus  finds 
himself  caught  in  the  net  of  habit.  The  deadening  effect  of 
automatic  work  upon  the  worker  is  greatest  where  the  reac- 
tions are  most  habitual,  and  where  the  activities  required 
are  simplest  and  least  varied  in  their  nature.  On  the  other 
hand,  where  the  work  of  the  day  is  varied — where  the  worker 
is  called  upon  to  make  a  large  number  6f  new  and  varied 
adjustments — there  his  mental  life  is  constantly  being  stimu- 
lated and  his  Activity  is  educative.  As  we  have  already  said, 
education  lies  in  the  process  of  forming  new  habits  of  behavior 
through  conscious  control,  and  development  ceases  when  these 
forms  of  behavior  become  fixed. 

In  the  primitive  method  of  learning  through  the  trial-and- 
error  method,  the  random  motor  activities  always  take  the 


410  PSYCHOLOGY 

direction  of  simplification  and  fixity  with  a  decreasing  accom- 
paniment of  consciousness.  But  in  the  higher  method  of 
learning  new  responses  through  conscious  representations,  the 
volitional  activities  may  take  two  directions:  (i)  Toward 
simplification,  regularity,  and  fixity  (habits),  with  decreasing 
consciousness  and  loss  of  plasticity;  or  (2)  toward  complexity 
and  variability,  with  increasing  consciousness  and  mental 
development.  In  the  latter  case,  volitional  activity  is  con- 
stantly enlarging  its  field  of  action  and  involving  the  mental 
processes  of  memory,  imagination,  deliberation,  comparison, 
and  judgment.1 

Genesis  of  Motor  Activity. — So  far  we  have  confined  our 
attention  to  the  motor  activity  as  we  find  it  going  on  in  the 
individual  organisms.  We  have  seen  that  each  individual 
inherits  a  stock  of  native  reactions,  out  of  which  he  builds  his 
future  behavior  through  the  aid  of  consciousness.  If  we  in- 
quire into  the  source  of  these  native  reactions  we  must  pass 
from  individual  to  racial  development.  How  did  these  or- 
ganic reactions  get  formed  in  the  first  place?  Were  they 
originally  conscious  reactions  from  which  consciousness  has 
lapsed,  or  were  they  formed  without  the  aid  of  conscious- 
ness? In  other  words,  was  consciousness  present  from  the 
beginning  of  organic  activity,  or  did  it  appear  after  the  origi- 
nal forms  of  activity  were  in  operation  in  the  living  organ- 
ism? The  problem  is  partly  biological  and  partly  psycho- 
logical, but  in  neither  science  is  there  a  sufficient  basis  of 
facts  to  solve  it.  Authorities  differ  in  their  theories:  Some 
hold  that  consciousness  was  present  at  the  beginning  of 
organic  life,  and  that  the  first  movements  of  the  first  organ- 
isms were  conscious  movements.  Later,  when  the  move- 
ments became  fixed,  consciousness  lapsed,  and  the  forms  of 
activity  were  then  passed  on  to  later  generations  by  heredity. 
The  instincts,  for  instance,  are  thought  to  be  originally  con- 
sciously controlled  activities,  which  through  repetition  be- 
*came  so  thoroughly  ingrained  in  the  organisms  that  they  no 
1  James:  "Principles  of  Psychology,"  chapter  on  "Habit." 


CONSCIOUSNESS  AND   BEHAVIOR  4!  I 

longer  needed  conscious  direction.  This  theory  of  the  origin 
of  instincts  is  known  as  the  "lapsed  intelligence  theory." 
The  following  facts  are  urged  as  evidence  in  support  of  the 
theory: 

1.  Habits  which  are  formed  under  the  direction  of  con- 
sciousness may  later  become  sufficiently  automatic  to  take 
place  without  the  aid  of  consciousness.     Instincts  may  have 
been  primitive  habits  which  are  preserved  by  heredity. 

2.  Many  of  the  purely  physiological  reflexes  and  instincts 
can  now  be  modified  by  conscious  direction.     This  fact  sug- 
gests an  original  conscious  control. 

3.  Certain  emotional  reflexes,  like  raising  the  nostrils  in 
contempt,  are  analogous  to  the  primitive  uncovering  of  the 
teeth  in  our  semihuman  progenitors  when  they  were  about 
to  attack  an  enemy.     The  emotional  reflexes  may,  therefore, 
be  survivals  of  earlier  conscious  action.1 

Other  authorities  believe  that  consciousness  appeared  in 
racial  development  after  the  physiological  reflexes  were  in 
operation,  and  that  the  first  movements  were,  therefore,  un- 
conscious reflexes.  The  Spencer-Bain  theory  of  the  origin  of 
consciousness  holds  that  life  was  at  first  without  conscious- 
ness. Consciousness  appeared  at  a  moment  of  neural  stress 
in  some  unusually  heightened  or  lowered  nervous  process — 
probably  in  both.  Instincts,  then,  are  the  accumulation  of 
unconscious  adaptive  reflexes  preserved  and  chained  together 
by  natural  selection.  This  is  known  as  the  "reflex  theory  of 
instincts."  Consciousness  was  at  first  vague  and  indefinite — 
mere  feelings  of  pleasure  and  pain — and  only  gradually  be- 
came aware  of  the  motor  activities  going  on  in  the  organism. 
Later  it  developed  to  the  point  where  it  could  image  and 
control  certain  of  the  reflexes.  This  marks  the  beginning  of 
voluntary  control. 

1Wundt:  "Physiol.  Psychol.,"  Ill,  p.  279;  "Outlines  of  Psych.,"  p.  213. 
Ward:  Art.  "  Psychology,"  in  Encycl.  Brit.,  XX.  Cope:  "Origin  of  the  Fittest." 
Titchener:  "Textbook  of  Psychology,"  p.  452.  Baldwin:  "Mental  Develop- 
ment," p.  208. 


412  PSYCHOLOGY 

The  main  objection  to  the  first  theory  is  that  it  seems  to 
demand  too  high  a  state  of  intelligence  in  the  first  primitive 
organisms.  Even  if  consciousness  were  present  in  the  first 
organic  movements,  it  seems  impossible  that  conscious  rep- 
resentation necessary  for  the  control  of  movement  could  be 
present.  The  most  that  could  be  reasonably  granted  is  a 
vague  organic  feeling  which  is  inadequate  as  a  directive 
agency.  Certainly  the  very  first  movement  of  the  first 
organism  had  no  conscious  experience  back  of  it  which  could 
serve  as  a  guide  for  its  response. 

The  second  theory  fails  to  make  clear  how  a  series  of  sim- 
ple reflexes  were  chained  together  when  only  the  last  reflex 
in  the  series  brought  about  any  gain  for  the  organism.  Again 
it  is  not  clear  how  an  organism  which  has  been  reacting  with- 
out consciousness  suddenly  acquires  it  merely  on  the  crest  of 
the  wave  of  heightened  neural  activity. 

Whatever  the  truth  may  be  about  the  first  reactions  in 
racial  development,  the  first  reactions  of  the  organism  are 
not  now  consciously  controlled.  For  some  time  the  child  is 
only  vaguely  aware  of  the  native  responses  which  are  ex- 
pressing themselves  without  his  direction.  It  is  not  until 
they  have  been  going  on  for  some  time  that  he  is  able  to  take 
affairs  into  his  own  hands  and  control  his  behavior. 

THE  CONNECTION  BETWEEN  CONSCIOUS  STATES  AND  ACTION 
—THE  LAW  OF  DYNAMOGENESIS 

All  forms  of  motor  activity  above  the  physiological  re- 
flexes involve  consciousness.  The  nature  of  the  conscious- 
ness involved  varies  from  mere  suggestion  to  action  to 
volitional  control  of  behavior.  In  the  native  and  acquired 
activities  consciousness  serves  in  the  capacity  of  suggestion. 
In  volitional  activity  consciousness  controls  as  well  as  sug- 
gests activity.  The  most  complete  connection  between  con- 
sciousness and  motor  activity  is  found  in  volitional  activity. 
Sin  far  a.s  WP  a,rp  able  to  o^gprYfii  r"?tihJPP'  gtandg  l^wgpr.  the 
conscious  representation  of  the  act  on  the  one. jtftg^  Apd  the 


CONSCIOUSNESS   AND  BEHAVIOR  413 

execution  of  the  act  on  the  other.  When  the  act  or  its  con- 
sequences are  imaged  and  the  consent  is  given,  the  opening 
of  the  motor  pathways  in  the  brain  seems  to  be  completed 
and  the  act  invariably  follows.  There  is  an  immediate  con- 
nection between  consciousness  and  action.  Some  of  the  con- 
nections are  native  and  some  are  acquired.  We  are  born 
with  definite  tendencies  to  act  in  certain  ways  when  certain 
conscious  experiences  come  to  us,  and  we  acquire  through 
experience  definite  tendencies  to  act  in  response  to  certain 
other  conscious  experiences.  We  may  say,  then,  that  every  j, 
conscious  state  tends  to  express  itself  in  some  form  of  motor/ 
activity.  This  principle  is  known  as  the  law  ofdynamopppesis.! 
Any  vivid  image  of  movement  always  involves  a  motor 
impulse  which  tends  to  bring  about  the  movement  imaged. 
Imagine  how  it  feels  to  bend  the  right  forefinger  and  note  the 
impulse  to  move  it.  In  some  cases  the  actual  movement  will 
take  place  without  any  definite  intention  to  move  the  finger. 
But  the  image  of  movement  is  not  always  necessary.  A 
large  part  of  our  daily  activities  are  movements  which  follow 
all  kinds  of  conscious  states.  Seeing  my  pen  on  the  floor,  I 
pick  it  up  without  consciously  imaging  the  movement.  If  I 
suddenly  remember  that  I  have  an  engagement,  I  start  for 
my  hat  and  coat  without  thinking  about  what  I  am  doing. 
Nearly  every  one  has  had  the  experience  of  performing  some 
act  unintentionally  which  had  been  thought  of  some  moments 
before,  but  which  had  in  the  meantime  dropped  out  of  con- 
sciousness. The  motor  pathway  was  unblocked  by  the  earlier 
thought,  and  the  act  appeared  at  the  first  opportunity.  Just 
this  morning  I  sat  down  at  my  desk  with  the  intention  of 
putting  away  some  letters  which  I  had  in  my  hand.  Hap- 
pening to  remember  an  engagement  which  I  had  made,  I 
took  out  my  watch  just  as  I  sat  down  and  noted  the  time, 
then  opened  the  drawer  of  the  desk  and  placed  the  watch 
where  I  had  intended  to  put  the  letters.  It  often  happens 
/that  in  conversation  we  use  some  word  or  phrase  just  after 
fvdetermining  not  to  use  it  for  fear  of  offending  a  friend.  The 

^ 


414  PSYCHOLOGY 

thought  opens  up  the  motor  pathway,  and  if  the  conscious 
inhibition  lapses  for  an  instant  the  expression  will  take  place, 
and  when  we  come  to,  we  realize  that  we  have  said  just  the 
thing  that  a  moment  before  we  determined  not  to  say.  In 
skilled  movements  there  is  oftentimes  a  strong  tendency  to 
repeat  an  error  again  and  again  immediately  after  its  first 
appearance,  simply  because  consciousness  of  the  first  error  is 
still  present  in  the  mind.  This  consciousness  acts  as  a  pre- 
disposition to  the  movement.  And  so  we  could  multiply  in- 
definitely illustrations  of  the  fact  that  mental  states  of  all 
\kinds  make  immediate  connections  with  motor  activity. 
/»  This  generalization  may  appear  too  sweeping.  The  im- 
/  plication  that  every  idea  which  appears  in  consciousness  is 
followed  by  a  fully  executed  bodily  reaction  is,  of  course,  not 
true.  Evidently  we  have  many  thoughts  which  do  not  find 
expression  in  behavior.  However,  we  have  reason  to  believe 
that  the  tendency  to  movement  is  present  in  every  mental 
state,  even  though  the  actual  movement  does  not  take  place. 
The  reason  for  its  failure  to  appear  rests  in  the  fact  that  it  is 
inhibited  by  the  dynamic  character  of  other  mental  states 
which  rise  in  the  mind  at  the  same  time.  In  the  lower  ani- 
mals mental  states  find  immediate  expression  in  motor  activ- 
ity. In  the  more  complex  mental  life  of  man  the  direct  ex- 
pression of  consciousness  is  often  modified  or  inhibited.  In 
the  very  young  child,  as  in  animals,  mental  states  find  imme- 
diate expression  in  motor  activity.  But  gradually,  as  the 
simplicity  of  mental  life  develops  into  greater  manifoldness 
and  complexity,  there  arises  the  possibility  of  conflict  between 
the  impulses  of  consciousness.  For  instance,  a  young  child 
with  limited  experience  will  grasp  the  bright  flame  of  a  can- 
dle if  it  is  placed  within  his  reach,  but  after  he  has  experi- 
enced the  painful  quality  of  fire  the  grasping  movement  is 
inhibited.  The  impulse  to  reach  for  the  flame  is  inhibited 
by  the  thought  of  "burnt  hand." 

The  more  complex  the  mental  state  the  fewer  are  the 
chances  for  direct  connection  with  motor  activity.     But  when 


^^n:  .^-- 

CONSCIOUSNESS   AND   BEHAVIOR  415 

ideas  are  clear  and  definite,  and  no  opposing  ideas  arise,  they 
lead  to  action.     Men  of  action  are  men  with  single  and  clear- 

The  connection  between  mental  states  and  bodily  activP" 
ties  is  such  that  the  character  of  consciousness  comes  in  time 
to  stamp  itself  upon  the  physical  appearance  of  the  individ- 
ual. The  outer  man  reveals  the  inner  man  so  faithfully  that 
we  need  not  wonder  at  the  revelations  of  the  so-called  "mind- 
readers" — most  of  them  persons  who  have  learned  the  art 
of  reading  the  character  of  thoughts  by  means  of  physical 
appearances  and  actions. 

If  we  consider  for  a  moment  the  law  of  dynamogenesis  in 
the  light  of  the  history  of  the  development  of  motor  activity, 
we  shall  be  able  to  get  a  still  clearer  view  of  the  dynamic 
character  of  consciousness.  In  the  beginning  every  stimulus 
is  transferred  immediately  into  action.  Through  the  process 
of  evolution  a  simple  nervous  system  is  developed  and  set 
aside  for  the  purpose  of  taking  over  the  function  of  transmit- 
ting stimulation  from  one  part  of  the  body  to  another.  Then 
the  brain  is  built  up  as  a  receiving  and  distributing  centre  for 
nerve  impulses.  Now  the  brain  retains  the  primitive  irri- 
tability of  tissue  in  that  the  nerve  impulses  which  reach  it 
from  sense-organs  are  communicated  to  the  organs  of  response 
—the  muscles.  The  tendency  to  communicate  stimulation  is 
the  same  as  in  the  primitive  state,  but  the  pathways  by 
which  transmission  takes  place  are  greater  in  number  and 
complexity.  Meantime  consciousness  has  definitely  appeared 
in  connection  with  the  activity  of  the  brain  centres.  Sensa- 
tions and  perceptions  now  aid  in  setting  up  immediate  re- 
sponses to  stimuli  through  the  reflexes  and  instincts.  Later, 
conscious  representation,  comparison,  and  judgment  appear 
and  make  possible  the  process  of  volitional  activity  by  means 
of  which  nervous  impulses  may  be  directed  into  definite 
directions,  or  even  inhibited.  While  consciousness  has  be- 
come a  definite  factor  in  the  psychophysical  activity,  the 
primitive  nature  of  nerve  impulses  has  not  been  changed. 


416  PSYCHOLOGY 

There  is  the  same  tendency  for  every  sensory  stimulation  to 
pass  directly  into  action.  Not  only  sensory  stimulation,  but 
thoughts  and  ideas  corresponding  to  higher-centre  activities 
show  the  same  primitive  dynamic  character. 

Control. — Just  as  in  the  beginning  simple  conscious 
states  were  connected  directly  with  organic  responses  and  so 
served  to  control  behavior,  so  now  in  its  highest  forms  con- 
sciousness is  still  directly  connected  with  motor  activity. 
The  rise  of  higher  forms  of  consciousness  has  not  changed 
the  nature  of  control;  it  has  only  made  it  more  complex. 
Rational  control  comes  from  the  presence  in  the  mind^of 
systems  of  ideas  which  check  and  countercheck  each  other 
injsuch^a  way  that  the  resultant  forces  run  out  into  the"par-. 
ticular  kind  of  behavior  appropriate  to  the  situation  which 


has  arousedj;hp  idpa^  The  control  of  our  motor  activities 
lies  in  the  ideas  which  we  allow  to  take  possession  of  us.  He 
who  would  follow  a  single  plan  of  behavior  must  allow  no 
ideas  but  those  in  keeping  with  the  plan  to  get  possession  of 
him.  If  he  does  he  will  find  that  they  will  be  real  forces, 
tugging  at  the  sinews  of  his  action  until  in  the  end  they  will 
master  him  and  force  him  to  fight  for  them. 

Effect  of  Motor  Activity  upon  Consciousness. — It  was 
asserted  in  the  beginning  of  the  chapter  that  consciousness 
both  determines  behavior  and  in  turn  is  determined  by  it. 
We  may  now  briefly  consider  the  second  part  of  this  princi- 
ple. The  sensations  of  movements  play  no  small  part  in  the 
content  of  consciousness.  Every  movement  of  the  voluntary 
muscles  gives  rise  to  kinassthetic  sensations  which  help  to 
determine  the  character  of  consciousness.  The  simple  ex- 
perience of  smell  is  partly  determined  by  the  sensations  of 
movement.  If  we  carefully  note  the  differences  between 
movements  (in  nostrils,  pharynx,  head,  respiratory  actions) 
made  when  we  are  smelling  some  displeasing  odor  like  that 
of  asafcetida,  and  the  movements  made  when  we  are  smell- 
ing the  odor  of  violets,  we  can  easily  detect  the  part  which 
sensations  of  movement  play  in  the  experience.  Sensa- 


CONSCIOUSNESS  AND   BEHAVIOR  417 

tions  coming  from  the  movements  of  turning  the  head  away, 
stuffy  sensation  in  pharynx  from  closing  the  back  air-passages 
and  inhibiting  respiration,  are  present  in  the  one  case  and 
absent  in  the  other.  The  content  of  consciousness  in  making 
definite  decisions  of  denial  plainly  contains  the  sensation^  of 
a^  peculiar  muscular  set  and  tension..  The  experiences  of 
scorn,  defiance,  anger,  and  vast  spatial  dimension,  contain 
very  markedly  characteristic  groups  of  muscular  sensations. 
Images  of  the  words  we  use  are  usually  in  terms  of  the  sensa- 
tions of  movements  made  in  speech.  Part  of  the  feeling  of . j  V^v 
self  consists  in  the  sensations  of  motor  reactions  which  arej\ 
going  on  in  our  muscles.  These  sensations  contribute  a  large 
share  in  determining  our  passing  moods  and  emotions. 

In  the  growth  and  the  development  of  consciousness,  dif- 
ferentiation of  motor  responses  is  an  important  factor  in 
breaking  up  and  organizing  vague  states  of  consciousness 
into  definite  experiences.  It  is  the  child's  motor  reactions 
toward  objects  which  make  them  definite  things  for  him  and 
set  them  off  from  other  objects.  His  different  ways  of  react- 
ing to  objects  analyzes  the  as  yet  undifferentiable  world  into 
elements  of  experience.  He  comes  to  know  as  one  thing 
that  to  which  he  reacts  with  a  single  characteristic  response. 
His  notion  of  "chair"  is  determined  by  the  fact  that  he  sits 
upon  it.  His  notion  of  "knife"  is  determined  by  the  reac- 
tions of  whittling;  of  "ball"  by  rolling,  throwing,  and  catch- 
ing. Each  object  in  his  at  first  rather  hazy  world  stands  out 
the  more  clearly  and  distinctly  as  his  reactions  to  it  become 
more  and  more  definite.  The  development  and  organization 
of  the  child's  knowledge  of  the  world  proceed  as  he  co-ordi- 
nates and  controls  his  motor  responses.  In  later  develop-- 
ment,  even  in  the  more  abstract  processes  of  thinking,  clear- » 
ness  and  orderliness  of  thought  are  the  result  of  the  forma- 1 
tion  of  clear-cut  and  definite  modes  of  action. 

Now,  while  the  sensations  of  movement  stimulate  con- 
sciousness, and  contribute  to  its  content  and  to  its  differentia- 
tion and  development,  there  is  another,  more  fundamental 


418  PSYCHOLOGY 

aspect  to  consider.  This  aspect  is  revealed  in  the  fact  that 
motor  activity  involves  open  and  active  brain  pathways. 
The  motor  centres  in  the  brain  form  a  drainage  area  for  the 
higher  associational  centres,  and  so  provide  for  and  invite 
greater  activity  in  these  centres.  We  often  find  ourselves  in 
some  situation  where  we  are  unable  to  collect  our  thoughts. 
Consciousness  is  at  a  standstill,  and  we  remain  empty-headed 
and  inactive.  Now  if  we  start  to  say  or  do  something,  no 
matter  what,  just  so  we  start  the  neural  mechanism  going, 
our  wits  come  back  to  us  and  we  gain  control  of  the  situa- 
tion. The  action  opens  up  the  neural  pathways  in  the 
brain.  Anything  that  tends  to  block  up  these  outlets  of 
motor  activity  tends  to  decrease  the  chances  for  the  rise  of 
consciousness.  The  greater  the  opportunity  for  response, 
provided  we  take  advantage  of  it,  the  higher  the  degree  of 
mental  development. 


CHAPTER  XIX 
WILL 

Conation.*— We  have  seen  that  consciousness  is  impulsive, 
i.  e.,  leads  to  motor  reactions.  This  dynamic  aspect  of  con- 
sciousness is  known  as  conation.  Conation  manifests  itself 
in  impulses  and  tendencies  to  action.  The  broadest  use  of 
the  term  conation  has  been  made  to  include  such  philosophi- 
cal concepts  as  that  of  the  "will  to  live,"  supposed  to  be  a 
more  or  less  blind  innate  tendency  within  us,  by  virtue  of 
which  we  are  impelled  to  life-preserving  activities.  The  so- 
called  "unconscious  will"  is  also  to  be  classed  among  these 
metaphysical  conceptions  of  the  fundamental  conative  aspects 
of  consciousness.  Such  conceptions  carry  with  them  the  im- 
plications that  some  cosmic  purpose  is  constantly  striving  to 
realize  itself  through  the  conative  tendencies.  In  psychol- 
ogy,  however,  conation  is^  used  in  a  narrower  sense,  indicating 
merely  that  consciousness  is  dynamic.  Every  state  of  con- 
sciousness  tends  to  culminate  in  motor  activity.  This  motor 
activity  manifests  itself  in  reflexes,  instincts,  ideo-motor 
movements,  habits,  and  volitional  reactions.  Some  of  these 
forms  of  reaction  are  inherited  and  some  are  acquired  through 
individual  experience.  Most  of  the  reflexes  and  all  of  the 
instincts  are  inherited,  while  the  ideo-motor  activities  and 
habits  are  acquired.  These  movements  follow  immediately 
upon  the  appearance  of  certain  mental  states.  Thus  the  per- 
ception of  a  hot  object  is  followed  by  the  withdrawing  reflex; 
the  presence  of  the  young  is  followed  by  the  parental  reac- 
tions; the  sight  of  the  door-knob  is  followed  by  the  move- 
ments of  opening  the  door;  the  sight  of  the  keyboard  of  the 
piano  and  the  music  score  is  followed  by  the  complex  series 
of  finger  co-ordinations  necessary  to  produce  the  music.  The 

419 


42O  PSYCHOLOGY 

reflexes,  instincts,  and  habitual  reactions  are  relatively  fixed 
and  invariable  in  character,  while  the  volitional  reactions  are 
highly  variable. 

We  have  noted  that  the  acquired  reactions  have  been 
<\     built  up  in  two  ways:  First,  by  means  of  the  method  of  trial 
\j)    and_error,  in  which  the  proper  reaction  comes  out  of  a  mass 
of  random  reflex  and  instinctive  movements,  and,  second, 
Q      by  means  .ofjEolirinnal  control.     Volitional  action  is  a  form 
of  conation  which  we  must  examine  more  thoroughly  than 
we  have  heretofore.     In  volitional  movement  we  deliberately 
"^    plan  andjjurposelv  execute  certain  act^,    All  psychologists 
agree  that  these  movements  are,  so  far  as  they  are  themselves 
concerned,  movements  or  combinations  of  movements,  which 
the  organism  has  already  made,  either  in  an  instinctive  or 
reflex  way.     Volitional  activity  then  consists  in  the  control 
of  movements  of  which  the  organism  is  already  capable. 

Will. — Is  volitional  activity  marked  off  from  the  other 
forms  of  activities  by  a  new  kind  of  conscious  element,  dis- 
tinct from  sensation  and  affection  or  any  of  their  compounds  ? 
Does  the  control  of  volitional  movements  arise  from  a  pure 
will  element  which  does  not  appear  in  the  non-volitional  re- 
actions?    So  far  introspection  has  failed  to  rf>vea,l-a:qy  new 
and  special  content  of  consciousness  which_jTPpar^  in  the 
*  {volitional  activities  and  which  can  be  looked  upon  asthe 
////  j  wilE     Where  observation  has  failed  to  give  us  facts,^ theory 
has   attempted   to   supplement  our  knowledge.     There   are 
any  theories  about  the  will.     Some  of  them,  the  spiritual- 
istic  theories,   consider  the  will  as  a  manifestation  of  the 
transcendental  ego  which  may  act  independently  of  the  laws 
governing  the  empirical  self.     Some  of  them,  the  empirical 
fa         theories,  consider  the  will  as  the  sum  of  the  conscious  im- 
•  A>^*pulses  or  directive  tendencies  found  in  the  conscious  states 
yj*\      themselves.     If  we  were  to  review  the  history  of  psychologi- 
cal thought,  we  should  find  that  the  will  has  been  variously 
considered.     At  times  it  has  been  identified  with  the  intellec- 
tual functions,  again  with  the  feelings  and  emotions,  and  still 


WILL  421 

again  it  has  been  considered  as  an  absolute  and  independent 
function  of  the  mind.  Accordingly,  the  conception  of  the 
will  has  varied  from  the  intellectualistic  point  of  view,  in  which 
the  will  is  derived  from  the  cognitive  processes,  to  the  volun- 
taristic  point  of  view,  in  which  it  is  the  central  point  of  all 
consciousness  and  the  basis  of  all  mental  life.  It  has  been 
looked  upon  both  as  a  fornL_Qf_je_eHng  and  as  a.  combination 
of  feeling  and  idea...  The  materialistic  point  of  view  has  con- 
sidered the  will  simply  as  a  combination  of  reflexes  grown  up 
in  the  course  of  evolution.  According  to  this  theory  the  will 
is  developed  out  of  the  automatic  reflexes  which  combine  into 
more  and  more  complex  forms,  while  at  the  same  time  con- 
sciousness is  developing  to  the  point  where  it  can  take  note 
of  these  movements  and  form  kinaesthetic  images  of  them. 
A  clear-cut  kinaesthetic  image  of  a  movement  becomes  the 
mental  side  of  willing.  Whenever,  according  to  a  modern 
form  of  the  reflex  theory,  we  image  a  movement  clearly  and 
vividly  and  hold  it  in  mind  before  the  movement  takes  place, 
we  then  feel  that  the  act  takes  place  by  our  own  volition. 

The  old  tripartite  division  of  the  mind  into  knowing,  feel- 
ing, and  willing  was  based  upon  the  "absolute  theory  of  the 
will,"  which  regarded  it  as  an  independent  and  co-ordinate 
elementary  function  along  with  cognition  and  affection.  The 
tendency  of  modern  psychology  is  to  leave  to  metaphysics 
speculation  about  the  ultimate  nature  of  the  will,  and  to 
confine  itself  to  the  study  of  specific  volitional  reactions  for 
the  purpose  of  determining  empirically  the  nature  of  these 
reactions. 

We  have  already  remarked  in  our  discussion  of  "con- 
sciousness and  action "  that  as  far  as  we  can  observe,  nothing 
in  the  nature  of  a  unique  will  element  stands  between  the 
consciousness  immediately  preceding  a  volitional  act  and  the 
movement  which  executes  it.  We  found  that  on  the  mental 
side  there  is  either  the  image  of  the  movement  to  be  made 
(resident  image)  or  the  image  of  some  result  of  the  movement 
(remote  image),  and  the  consent  or  intention  that  the  move- 


422 


PSYCHOLOGY 


ment  be  carried  out.  James  says  that  an  anticipatory  idea 
of  the  movement's  sensible  effect  (resident  or  remote)  "and 
the  fiat  is  all  that  introspection  can  discover  as  the  conscious 
forerunner  of  a  volitional  act.  By  the  fiat  hejrneans  holding, 
the  idea  before  the  mind  to  the  exclusion  of  other  antagonistic 
^ioleas.  The  prevalence  of  the  idea  in  the  mind  terminates 
tthe'"\jdlling  and  the  act  takes  place  mechanically.  Only  when 
j4^as  of  competing  or  antagonistic  acts  arise  does  the  will 
manifest  itself.  Then  the  strain  of  the  attention  to  hold  one 
of  the  ideas  before  the  mind  is,  according  to  James,  the  fun- 
damental act  of  the  will.  The  will  is  therefore  a  psychic  act 
— to  fill  the  mind  with  the  idea,  to  keep  affirming  and  adopt- 
ing a  thought  which  if  left  to  itself  would  slip  away — that  is 
the  inward  volitional  act,  says  James.  Accordingly,  volition 
presupposes  deliberation  in  which  different  alternatives  are 
presented  to  the  mind.  These  rival  lines  of  action  alternate 
in  consciousness — first  one  and  then  the  other  is  attended  to 
— until  attention  finally  fixes  upon  one  to  the  exclusion  of  all 
others.  The  decision  or  choice  is  the  holding  of  the  given 
idea  of  action  fast  in  the  mind.  When  this  is  done  we  con- 
sent to  the  reality  of  the  idea. 

Many  psychologists  believe  that  the  control  of  move- 
ments is  primarily  brought  about  through  the  effect  of  the 
kinaesthetic  images  (resident  images)  of  the  movements.  The 
image  of  the  movement  in  some  way  unblocks  the  neural 
pathways  leading  to  the  proper  muscles  and  the  nervous 
energy  drains  into  them  and  brings  about  the  movement. 
Recent  investigations  of  the  control  of  movement  indicate 
that  more  prominence  should  be  given  to  the  sensations 
awakened  by  the  movement  itself  as  a  factor  of  control  in 
the  following  stages  of  the  movement.  The  control  of  a 
movement  requires  awareness  of  the  position  of  the  parts  of 
the  body  moved  before  the  movement  begins.  This  means 
that  each  moment  of  kinaesthetic  sensory  experience  becomes 
the  cue  for  the  following  movements.  This  becomes  very 
evident  if  we  note  the  contents  of  consciousness  during  the 


WILL 


423 


act  of  throwing  at  a  mark  or  in  jumping.  Here  the  control  is 
brought  about  more  by  present  sensations  than  by  images 
of  past  movements  or  by  images  of  previous  results  of  similar 
movements.  Moreover,  not  only  the  sensations  of  moving 
muscles,  but  the  more  remote  visual  sensations  coming  from 
the  target,  the  height  from  which  we  are  to  jump,  and  other 
characteristics  of  our  surroundings,  are  important  factors  in 
the  control  of  movements.  As  we  have  previously  indicated, 
pathological  conditions  in  which  the  sensory  nerves  from  the 
muscles  are  so  affected  that  the  patient  cannot  sense  the 
movements  or  positions  of  the  parts  of  the  body,  result  in 
the  inability  to  control  movements,  although  the  motor 
nerves  running  to  the  muscles  from  the  brain  are  intact. 
Lack  of  sensations  of  movement  means  lack  of  control  of 
movements.  Such  a  condition  is  found  in  cases  of  locomotor 
ataxia. 

Neither  the  anticipatory  image  of  an  act  (resident  image) 
nor  the  image  of  the  result  or  consequence  of  the  act  (remote 
image)  nor  the  kinassthetic  sensations  of  the  movements  con- 
stituting the  act  give  us  a  new  form  of  consciousness  which 
we  can  call  a  will  element.  If  there  is  such  a  thing  as  a  pure 
will  element  in  consciousness  it  has  been  playing  hide-and- 
seek  with  us.  A  few  paragraphs  back  we  said  there  were  cer- 
tain exceptions  to  the  statement  that  in  careful  experimental 
work  on  the  will-  introspection  had  failed  to  detect  any  special 
will  element  in  volitional  activities.  Ach  and  Michotte  claim 
that  they  are  able  to  detect  a  will  element  which  is  present  in 
all  volitional  activities.  They  report  that  they  find  what 
they  call  an  actual  moment  in  which  there  is  a  content  which 
can  be  described  only  by  the  phrase  "I  will  actually."  They 
claim  that  this  conscious  content  is  that  of  a  subjectively  de- 
termined act — ajjure  will  act.  This  is  found  only  in  voli- 
tional acts  and  differentials  them  from  all  other  forms  of 
action.  In  this  "actual  moment"  the  "I"  is  taken  as  the 
cause  of  the  reaction,  and  therefore  we  are  conscious  of  an 
egoistic  control,  or  self-determined  act.  It  is  rather  difficult 


424  PSYCHOLOGY 

to  determine  just  how  far  the  metaphysical  conception  of  the 
self  or  subject  of  consciousness  has  influenced  the  introspec- 
tion in  these  cases.  There  is  no  questioning  the  fact  that  in 
volitional  acts  we  feel  that  we  are  originating  and  determin- 
ing the  movements.  James  refers  to  this  experience  as  an 
illusion,  and  Miinsterberg  considers  it  merely  the  anticipatory 
consciousness  of  the  act.  Other  psychologists  who  hold  that 
consciousness  is  a  real  agency  operating  between  the  recep- 
tion of  stimuli  and  the  motor  response,  and  therefore  effective 
in  determining  behavior,  believe  that  the  will  element  is  to 
be  found  in  certain  directive  tendencies  of  consciousness 
which  they  claim  transcends  the  limits  of  a  mere  assemblage 
of  elements.  The  " imageless- thought  psychologists,"  some 
of  them  at  least,  are  inclined  to  believe  that  the  control  of 
volitional  movements  may  be  brought  about  by  a  pure 
thought  element  which  is  a  directive  conscious  tendency  over 
and  above  the  conscious  contents  of  sensations  and  anticipa- 
tory images  of  the  movements.  Ogden,  for  instance,  in  his 
"Introduction  to  General  Psychology,"  has  outlined  an  inter- 
action  theory  of  mind  which  admits  a  purposive  activity  in 
consciousness.  This  active  principle  works  independently  of 
the  laws  of  association  and  is,  therefore,  a  new  determining 
factor  in  consciousness.  Thus  we  have  a  basis  for  the  will. 
He  recognizes  three  modes  of  directive  tendencies:  First, 
physiological  impulses  found  in  the  reflexes;  second,  directive 
tendencies  which  arise  from  association  complexes,  such  as 
those  found  in  habits  of  action;  and  third,  egocentric  tenden- 
cies in  which  we  are  conscious  of  a  "personal  moment"  as 
directing  the  course  of  our  thinking  and  acting.  Hence  we 
have  real  self-activity  which  is  a  direct  manifestation  of  the 
ego.  While  some  of  our  activities  are  the  result  of  a  physio- 
logical casual  order,  and  some  are  the  result  of  the  laws  of 
association,  yet  a  direction  can  be  given  to  these  activities 
by  the  purposive  or  egocentric  tendencies.  This  conception 
of  a  directive  tendency  in  consciousness  is  an  attempt  to 
escape  a  purely  mechanical  conception  of  life  in  which  con- 


WILL  425 

sciousness  must  be  considered  as  a  mere  epiphenomenon — a 
spectator  of  what  is  going  on,  but  in  no  way  effective  in  de- 
termining the  course  of  behavior. 

Will  as  Self-Determination. — It  is  quite  plain  that  the 
most  popular  way  of  thinking  about  the  will  is  to  consider  it 
as  the  activity  of  a  self  or  ego.  It  is  the  self  which  makes 
our  decisions  for  us  and  determines  the  kind  of  behavior 
manifested  in  our  volitional  acts.  Now  such  a  conception 
involves  the  metaphysical  subject  side  of  consciousness  to 
which  attention  was  called  in  the  first  chapter  of  the  book. 
It  was  there  pointed  out  that  it  is  only  the  content  side  of  con- 
sciousness that  can  be  observed.  We  have  no  empirical 
knowledge  of  the  subject  or  ego  which  is  supposed  to  know 
and  feel  and  will  for  us.  Only  the  content  of  consciousness 
is  revealed  to  introspective  observation.  If,  therefore,  some 
one  asserts  that  the  self  does  our  willing  we  are  unable  to 
affirm  or  deny  the  statement  upon  the  basis  of  observed  facts. 
If  it  seems  reasonable  to  believe  that  back  of  the  conscious 
states  themselves  there  is  a  self  or  ego  which  is  responsible 
for  them,  then  we  must  consider  it  only  as  a  theory  and  not 
as  a  fact.  What  we  really  need  to  know,  however,  is  what 
the  will  is  as  content  of  consciousness.  So  far  we  have  been 
unable  to  find  any  unique  and  separate  will  element  on  the 
content  side  of  consciousness  beyond  the  resident  and  remote 
images  and  sensations  preceding  and  accompanying  our  voli- 
tional acts,  and  the  consciousness  of  a  purpose  or  intention. 
These  are  all  cognitive  factors. 

It  has  been  suggested  that  in  all  cases  where  we  exert  will 
power  to  decide  upon  some  line  of  action,  we  feel  the  effort  . 
of  the  will.     Is  this  not  the  will  element  or  content  that  we  ' 
have  been  looking  for?     It  is  generally  agreed,  however,  that  I 
this  feeling  of  effort  in  volitional  activity  is  the  sensation  of  I 
muscular  strain  coming  from  the  forehead  and  chest  and  t 
other  parts  of  the  body  during  the  moments  of  deliberative 
attention  required  in  deciding  between  alternative  courses  of  I 
action.    We  know  that  at  such  times  we  innervate  certain 


426  PSYCHOLOGY 

muscles,  especially  those  of  the  head  and  those  controlling 
the  respiratory  organs. 

It  has  also  been  suggested  that  the  so-called  "feeling  of 
innervation"  is  a  will  factor  or  representation  of  the  will 
consciousness.  The  feeling  of  innervation  is  supposed  to  be 
the  consciousness  of  nervous  energy  or  nerve  impulses  sent 
out  from  the  brain  centres  to  the  appropriate  muscles,  whose 
activity  is  required  in  carrying  out  volitional  acts.  If  we 
were  not  able  to  sense  this  outgoing  nerve  energy,  how  could 
we  tell  how  much  to  send  out  and  to  what  particular  mus- 
cles? It  is  claimed  that  in  volitional  movements  we  are 
conscious  in  advance  both  of  the  amount  and  the  direction 
of  the  nervous  energy  involved  in  the  movements,  and  that 
this  Consciousness  is  the  feeling  of  innervation.  Here  is  a 
first-hand  conscious  uunluir  which  apparently  originates  in 
and  is  controlled  by  the  will,  and  not  the  conscious  content 
made  up  of  images  of  past  movements,  as  our  analysis  has 
shown  the  contents  of  volitional  consciousness  to  be.  But 
the  doctrine  of  the  "feeling  of  innervation"  has  not  been 
accepted.  There  is  no  evidence  that  we  are  in  any  way 
aware  in  advance  of  the  nervous  discharge  from  the  brain 
centres  to  the  muscles.  James,  who  does  not  believe  in  the 
"feeling  of  innervation,"  says:  "The  discharge  into  the 
motor  nerves  is  insentient,  and  all  our  ideas  of  movement,  in- 
cluding those  of  the  effort  which  it  requires,  as  well  as  those 
of  its  direction,  its  extent,  its  strength,  and  its  velocity,  are 
images  of  peripheral  sensations,  either  'remote,'  or  resident 
in  the  moving  parts,  or  in  o'trier  parts  which  sympathetically 
act  with  them  in  consequence  of  the  diffusive  wave."1  We 
are,  therefore,  just  where  we  were .  in  the  beginning  of  our 
search  for  a  self-determining  consciousness,  or  will  content. 
The  feelings  of  effort  and  whatever  there  is  of  observable 
experience  in  the  "feeling  of  innervation"  are  kinaesthetic 

1  "Principles  of  Psychology,"  vol.  II,  p.  493.  For  a  refutation  of  the  doc- 
trine of  the  feeling  of  innervation  the  student  is  referred  to  pages  493-518  of 
that  volume. 


WILL  427 

sensations  originating  in  muscular  strain.     They  are,  there- 
fore, not  consciousness  of  the  will. 

If  we  discard  the  older  metaphysical  view  of  the  self  as  a 
subject  or  ego,  and  look  upon  the  self  (from  the  content  point 
of  view)  as  an  organized  body  of  conscious  content  made  up 
of  knowledge,  thoughts,  desires,  and  ideals  which  have  grown 
up  through  experience  and  have  formed  a  nucleus,  or  per- 
sonality, we  may  be  able  to  get  a  clearer  conception  of  the 
volitional  process  as  a  self -determining  activity.  First  of  all, 
however,  we  must  understand  that  the  act  of  willing  is_  a 
psychical  process^  The  physical  movements  which  carry  out 
the  inner  will  process  are  merely  the  physiological  results^  of 
the  willing'  The  settling  of  the  mind  upon  a  course  of  action 
and  holding  it  fast  in  the  field  of  attention,  that,  as  James 
has  said,  is  the  real  act  of  will — the  fiat^  or  settlement  by  the 
self  of  a  mental  issue.  Now,  what  idea  gains  the  attention 
and  holds  it  and,  therefore,  finds  expression,  depends  upon 
the  nature  of  the  knowledge,  thoughts,  desires,  and  ideals 
which  make  up  the  self.  Whatever  idea  is  felt  as  foreign  to 
the  empirical  self  at  the  moment  of  decision,  is  rejected,  but 
whatever  idea  is  in  harmony  with  the  self  uppermost  at  the 
time  is  reinforced  by  the  self-feelings  and  becomes  identified 
with  the  self.  In  a  more  popular  way  we  say  that  we  are 
interested  in  certain  things  and  ideas — that  a  given  idea  is 
at  the  time  the  most  interesting  project  before  us.  It  is, 
therefore,  the  nature  of  the  self  which  determines  what  addi- 
tions  to  itself  are  to  be  made.  Whatever  fits  harmoniously 
into  the  system  of  conscious  states  which  constitutes  the  self 
at  the  time  is  accepted.  The  impelling  force  of  an  idea  or 
imaged  line  of  action  is  determined,  therefore,  by  the  self 
and  the  selection  or  choice  of  action  is  made  by  the  self. 
Sometimes  only  a  small  and  fragmentary  part  of  the  self  is 
active  in  making  its  decisions.  Overhasty  actions  result. 
In  such  cases  the  volitional  process  is  not  representative  of 
the  true  self.  A  passing  desire  may  be  indulged,  or  an  idea, 
illuminated  by  the  momentary  flash  of  passion,  may  be  given 


428 


PSYCHOLOGY 


the  right  of  way  before  all  the  forces  of  the  self  are  given  time 
or  opportunity  to  take  part  in  determining  the  issue.  A  per- 
sonality which  allows  a  single  idea,  or  the  first  thing  that 
enters  the  mind  to  find  expression  before  it  can  be  reviewed 
by  the  larger  self,  may  be  said  to  possess  an  impulsive  will 
or  an  "explosive  will,"  as  James  puts  it.  Defective  inhibi- 
tory powers  are  found  in  such  a  personality.  The  will  in  the 
larger  sense  functions  not  only  in  a  positive  way  in  bringing 
about  co-ordinated  action,  but  also  in  a  negative  way  by 
checking  or  inhibiting  impulsive  action.  Isolated  ideas  and 
desires  (ideas  and  desires  not  fully  co-ordinated  with  the 
organized  body  of  knowledge)  are  impulsive,  but  when  the 
ideas  are  organized  and  the  desires  co-ordinated  into  a  sys- 
tem, so  that  each  is  fixed  in  relation  to  the  others,  then  the 
impulsive  character  of  this  larger  self  becomes  volitional. 

Since  the  self  is  a  very  complex  conscious  organization 
(containing  tendencies,  impulses,  and  desires,  some  of  them 
native  and  racial  and  some  of  them  acquired  and  ideal),  con- 
flicts between  the  different  tendencies,  impulses,  and  desires 
are  sure  to  arise.  The  self  is  then  arrayed  against  the  self. 
No  issue  can  take  place  until  the  conflicting  and  antagonistic 
parts  of  the  self  are  reduced  to  a  single  system  of  impulses. 
This  may  take  place  either  by  the  suppression  of  all  but  one 
group  of  impulses,  or  by  the  union  and  modification  of  all 
the  impulses  into  a  single  system.  Volitional  control  really 
consists  in  the  acceptance  of  ideas  by  the  organized  body  of 
conscious  states,  which  we  have  called  the  self.  Will  is  not 
a  new  and  separate  mental  element  existing  alongside  our 
other  mental  elements,  nor  is  it  a  mental  factor  which  by  its 
own  force  represses  our  instinctive  tendencies  and  primitive 
impulses,  but  it  is  the  conative  or  dynamic  side  of  all  our 
consciousness  in  so  far  as  it  is  organized  into  a  united  self— 
as  Angell  expresses  it,  "The  whole  mind  active,  this  is  the 
will." 

Will  and  Knowledge. — From  the  foregoing  it  is  evident 
that  the  exercise  of  the  will  presupposes  a  supply  of  ideas 


WILL 

left  in  the  mind  by  previous  experience.  In  fact  there  is  no 
will  apart  from  knowledge.  It  is  just  at  those  points 
pur  information  is  meagre  that  we  show  weak  conative  ten- 
dencies,. We  hesitate  and  waver  and  delay  in  taking  a  de- 
cided  stand  when  we  do  not  possess  definite  knowledge.  We 
are  most  easily  influenced  by  agencies  outside  our  own  self 
under  such  conditions.  On  the  other  hand,  we  are  most  de- 
cided  just  where  we  have  master£d_the  facts_about_us"  In 
many  cases,  however,  we  are  not  master  of  the  facts  and  we 
must  decide  the  issue  from  a  limited  point  of  view.  All  that 
can  be  expected  under  these  circumstances  is  that  we  make 
use  of  all  the  possibilities  within  us — that  we  bring  to  bear 
upon  the  problems  all  the  relevant  knowledge  we  possess,  to 
the  end  that  our  decision  springs  out  of  the  whole  self  and 
not  out  of  a  fragment  of  it.  The  man  with  a  healthy  and 
vigorous  will  is  the  man  whose  knowledge  is  varied  and  ex- 
tensive enough  to  allow  him  to  look  on  all  sides  of  any  given 
question  calling  for  his  decision.  To  be  able  to  think  clearly 
is  a  necessary  attribute  of  a  prompt  and  forceful  will.  On 
the  other  hand,  hazy  knowledge  leads  to  doubt  and  indeci- 
sion, which  is  the  characteristic  of  a  weak  and  inefficient  will. 

Will  and  Character. — While  it  is  true  that  the  nature  of 
our  volitional  action  depends  upon  the  kind  of  character  we 
have,  it  fc  pr^hly  Q"Qr*  m™-**  fnnHam^ritallv  true  that  the 
kind  of  character  we  develop  depends  upon  -fehe"jym.     For 
character  is  the  fixation  of  modes  of  willing- — choices  organ- 
ized into  habits.     Every  decision  made  adds  to  and  strength- 
ens the  self  in  the  particular  line  of  thinking  and  acting  which 
is  involved  in  the  decision.     The  man  who  has  leo^  an  up- 
right life  is  unablejto^wilLa  dishonorable  apt.    The  character  ^ 
of  his  self  has  been  formed  by  years  of  willing,  according  to   4 
the  principles  of  honesty  and  square  dealing,  and  these  prin-^i 
ciples  have  become  so  important  a  part  of  his  self  that  they 
are  always  on  hand  on  all  occasions  of  deliberation  and  choice. 

Freedom  of  the  Will. — We  cannot  take  up  a  discussion  of 
the  freedom  of  the  will  without  entering  into  philosophical 


430  PSYCHOLOGY 

considerations.  Within  the  limits  of  scientific  psychology  we 
have  no  method  of  approaching  the  larger  question  of  the 
freedom  of  that  system  of  conscious  states,  which  make  up 
the  self,  and  which  is  supposed  to  be  dominated  by  the  will. 
As  far  as  we  know,  all  the  observable  elements  which  consti- 
tute the  self  are  definitely  and  causally  related  to  each  other 
and  the  rise  and  fall  of  the  elements  within  the  self  takes  place 
in  an  orderly  way,  according  to  psychological  laws.  We  can 
find  no  conscious  element  which  is  not  subject  to  these  laws. 
Freedom  in  the  sense  of  absence  of  law  is  a  conception  which 
transcends  the  limits  of  psychology.  But  since  the  question 
of  the  free  will  is  bound  to  be  raised  in  the  minds  of  those 
who  approach  the  study  of  the  will  for  the  first  time,  we  can 
profitably  give  it  a  brief  consideration  in  order  that  we  may 
at  least  understand  the  nature  of  the  problem.  Although  we 
believe  that  we  are  free  to  choose  between  different  lines  of 
action,  we  shall  find  when  we  examine  the  matter  carefully 
that  there  are  many  difficulties  in  the  way  of  this  belief. 

There  are  two  philosophical  theories  about  the  freedom  of 
the  will:  First,  determinism,  and,  second,  indeterminism. 
Determinism  holds  that  every  will  act  comes  out  of  pre-exist- 
ing conditions  of  the  self.  According  to  this  theory,  we  are 
bound  to  choose  in  accordance  with  the  nature  of  the  self. 
Our  will  is  determined  by  our  interests,  desires,  and  ideals, 
which  depend  upon  what  we  inherit  and  what  we  acquire 
through  experience — upon  what  we  are  by  nature  and  what 
we  are  by  nurture.  No  one  is  free  from  these  influences.  In- 
determinism, on  the  other  hand,  holds  that  the  will  is  not 
determined  by  previous  conditions  and  surroundings  of  the 
self.  The  most  radical  form  of  this  theory  considers  that 
will  is  absolutely  independent  of  any  motive  for  action  what- 
ever. According  to  this  theory,  it  is  the  will  which  determines 
motives  for  actions,  while  the  will  itself  is  not  bound  in  any 
way.  No  antecedent  condition  of  the  self  has  anything  to 
do  with  the  will.  What  I  will  to  do,  for  instance,  is  unpre- 
dictable even  by  an  intelligence  that  is  acquainted  with  my 


WILL  431 

entire  past  experience  and  the  native  characteristics  inherited 
from  my  parents. 

Since  psychology  looks  upon  the  self  as  a  system  of  con- 
scious elements  which  has  grown  up  in  a  rational  way,  and 
can  be  accounted  for  by  psychological  principles,  it  is  evi- 
dent that  we  cannot  accept  the  theory  of  indeterminism.  A 
wholly  free  and  capricious  mental  element  which  is  not  influ- 
enced by  pre-existing  conditions  and  present  surroundings  is 
beyond  psychological  explanation.  In  a  certain  way  we  may 
think  of  the  will  of  man  as  free,  especially  when  we  compare 
him  with  the  lower  animals.  The  animals  are  controlled  much 
more  than  we  by  the  conditions  of  the  present  moment, 
since  their  behavior  depends  upon  the  nature  of  the  present 
stimulus.  Man,  on  the  other  hand,  is  not,  as  they  are,  the 
puppet  of  the  moment,  but  transcends  the  immediate  condi- 
tions of  his  environment.  He  is  free  from  the  demands  of 
the  moment  in  that  he  is  able  to  recall  past  experiences,  for- 
mulate them  into  principles  and  ideals,  and  use  them  as  guides 
or  cues  of  action.  He  may,  therefore,  adjust  himself  to  more 
remote  conditions  which  are  not  present  in  the  immediate 
environment.  In  this  sense  man  is  free  in  just  so  far  as 
his  action  springs  from  the  broader  field  of  past  experiences 
rather  than  from  the  narrower  experience  of  the  present 
moment. 

Psychologically  considered,  every  volitional  activity  can, 
if  we  know  all  the  facts  surrounding  it,  be  fully  accounted 
for  by  psychological  principles.  Really  the  only  meaning  of 
the  term  "free  will"  that  is  compatible  with  the  principles 
of  psychology  is  that  which  considers  the  will  free  in  so  far 
as  it  is  not  constrained  by  external  factors  but  has  the  oppor- 
tunity of  following  out  its  own  nature.  In  so  far,  then,  as 
we  are  not  subject  to  influences  external  to  ourselves  and  can 
act  according  to  the  dictates  of  our  own  nature,  we  are  free.  I 


The  Unity,  Continuity,  and  Identity  of  Personal  Conscious- 
ness.— So  far,  we  have  been  engaged  in  the  task  of  examining 
conscious  life  in  a  piecemeal  fashion.  In  each  chapter  we 
have  isolated  and  described  some  one  aspect  of  consciousness, 
neglecting  for  the  time  its  other  aspects.  This  analytic  pro- 
cedure is  necessary  in  order  that  we  may  come  to  a  better 
understanding  of  the  whole  conscious  organization.  But  we 
must  not  stop  here,  for  the  discrete  mental  elements  have 
no  meaning  when  standing  alone.  As  a  matter  of  fact,  we 
never  find  a  sensation,  a  percept,  a  memory,  a  reasoning 
process,  a  feeling,  an  emotion,  or  a  will  act  existing  by  itself. 
Sometimes  one  of  these  aspects  of  consciousness  is  dominant 
and  sometimes  another,  but  whether  it  is  perception,  or 
memory,  or  emotion,  or  reasoning,  it  is  not  the  only  mental 
state  or  process  present  at  the  moment.  In  each  case  there 
is  something  more — a  background  of  consciousness  represent- 
ing an  organized  and  unified  content  which  hangs  together  in 
a  unique  and  personal  way.  Whatever  is  thrown  upon  the 
surface  of  consciousness  is  projected  there  momentarily  as  a 
lesser  content  upon  a  larger  and  more  persistent  content. 
No  single  experience  stands  alone  in  consciousness,  but  is 
outlined  against  other  experiences  which  lie  outside  the  focus 
of  attention.  Organic  and  bodily  sensations,  aches  and 
pains,  marginal  visual  and  auditory  presentations,  fading 
images  of  experiences  just  past,  memories  of  remote  or  recent 
scenes,  hopes  and  desires  and  plans  for  the  future  make  up 
this  background.  If,  for  instance,  the  messenger-boy  hands 
me  a  telegram  announcing  the  death  of  a  friend,  the  emotion 
which  the  news  produces  and  the  thought  concerning  the 

432 


THE   SELF  433 

future  of  his  family  are  both  experienced  within  the  larger 
conscious  content  of  myself  writing  a  chapter  on  the  self, 
plus  the  visual  appearance  of  the  top  of  my  desk  and  the 
familiar  sound  of  my  neighbor's  children  playing  outside, 
plus  the  feeling  of  hunger  resulting  from  a  delayed  luncheon. 
All  these  experiences  and  many  more  lie  in  the  background 
of  the  consciousness  which  is  experiencing  the  emotion. 

Then,  too,  consciousness  is  not  made  up  of  a  series  of 
separate  and  discrete  mental  states.  On  the  other  hand, 
there  is  a  marked  continuity  in  the  different  experience  of 
every  individual.  Each  experience  overlaps  the  experiences 
which  precede  and  follow  it,  so  that  there  is  a  continuous 
unity  in  each  individual  stream  of  consciousness.  As  new 
and  different  experiences  appear  they  do  not  come  as  sharp 
breaks  in  consciousness  but  as  modifications  of  the  growing 
unity  of  experiences.  The  growth  of  the  cumulative  experi- 
ence is  so  gradual  that  there  remains  a  sufficient  conscious 
background  of  old  experience  to  give  the  whole  a  self-identity. 
There  is  no  moment  in  the  normal  waking  life  where  this 
unity,  continuity,  and  identity  of  conscious  experiences  can 
be  disregarded.  There  is,  then,  an  organization  of  experience 
into  a  personal  unity  in  which  all  aspects  an^;  processes  of 
consciousness  are  represented.  This  complex  organization  is 
the  self. 

The  Subject  Self,  or  Ego. — From  the  very  earliest  times 
philosophers  have  noted  the  unity,  continuity,  and  identity 
of  the  personal  consciousness  and  have  sought  to  explain  this 
unity  by  assuming  that  back  of  the  conscious  states  them- 
selves there  exists  for  each  individual  a  single  unanalyzable 
subject  self,  or  ego,  to  which  the  various  parts  of  his  experi- 
ence are  presented  and  unified.  Without  this  self,  or  ego, 
there  would  be,  it  was  thought,  no  means  of  binding  together 
the  different  elements  of  experience  into  any  kind  of  unity; 
and  further,  without  such  a  unifying  entity,  there  could  be  no 
continuity  or  identity  of  experience.  The  idea  of  the  dual 
nature  of  the  self  rests  upon  this  logical  assumption,  and  has 


434  PSYCHOLOGY 

found  its  way  into  popular  thought.  It  seems  reasonable  to 
suppose  that  all  the  various  experiences  of  an  individual  must 
be  presented  to  some  single  subject  self  whose  function  it  is 
to  organize  them  into  a  personal  whole.  James  refers  to  the 
two  aspects  of  the  self  as  the  "knower"  and  the  "known"  or 
the  "7"  and  the  "me."  Kant  uses  the  terms  pure  ego  and 
empirical  self  to  designate  the  subject  side  and  the  content 
side  of  the  self. 

The  difficulty  with  such  a  conception  of  the  self  in  psy- 
chology lies  in  the  fact  that  the  subject  self  or  ego  eludes 
observation,  and  the  statements  concerning  it  can  never  be 
checked  up  by  actual  experience.  If  we  adhere  strictly  to 
the  facts  of  conscious  life,  we  must  give  up  the  conception  of 
jhe_transcendental  ego,  or  subject  self,  and  turn  to  the  con- 
tent side  ofomsciousness  and  try  to  find  the  principles  of 

of  the  self,  in  the  experiences 


mselyes.  ,We  can.  JLlhink.  make  out  a  self  purelyjm  an 
empirical  basis.  We  shall  then  have  no  need  for~5ie~rrieta- 
physical  conceptionof  a  seh^a^kjfTand^independeiit  of  the 
mental_sta,tes  whichjxmstitute  actual  expejiejicg. 

The  Empirical  Self.  —  If  the  discrete  mental  states  cannot 
be  attributed  to  an  independent  self,  or  psychical  being  be- 
yond the  mental  states  themselves,  then  they  must  be  attrib- 
uted to  the  empirical  self,  or  complex  of  mental  states  —  to 
that  complex  which  constitutes  the  relatively  invariable  and 
persistent  background  of  our  conscious  life.  The  empirical 
self  is  that  central  and  intimate  core  of  conscious  content 
made  up  of  the  bodily  sensations,  familiar  thoughts  and  ideas, 
memories,  feelings,  and  desires.  If  now  we  grant  to  this 
background  of  consciousness,  activities,  tendencies,  and  im- 
pulses, then  we  have  a  self-active  conscious  content  which 
is  capable  of  taking  up  new  content  into  itself.  In  this  way 
the  empirital  self  takes  on  the  function  of  the  "  knower." 
The  dynamic  aspect  of  the  self  is  determined  by  the  nature 
of  the  elements  entering  into  the  conscious  states  dominant 
at  any  one  moment.  Since  all  consciousness  is  functional 


THE   SELF  435 

the  self-content  is  also  functional.  The  empirical  self  is, 
therefore,  never  simply  a  passive  self,  for  while  it  is  receptive 
in  so  far  as  it  receives  new  content,  it  is  also  active  in  so  far 
as  it  incorporates  or  apperceives  this  new  material  into  the 
old.  The  conception  of  the  self  as  passive  is  limited  to  the 
self  when  it  is  receiving  impressions  from  without,  as  in  sen- 
sation and  perception.  Even  here  the  reception  of  impres- 
sions from  without  cannot  take  place  without  apperceptive 
activity  of  older  experiences  already  in  the  mind.  The  cen- 
tral mass  of  content  is  always  active  in  some  degree.  It  is, 
of  course,  most  active  and  directive  in  acts  of  will. 

The  identity  of  the  empirical  self  is  manifest  in  the  fact 
that  no  content  can  be  assimilated  without  a  body  of  old 
experiences  which  serves  as  a  basis  of  interpretation.  The 
fact  of  recognition  in  itself  is  evidence  of  the  activity  of  the 
empirical  self.  The  unity  of  the  empirical  self,  together  with 
its  continuity  and  identity,  we  have  already  pointed  out  in 
the  first  paragraph  of  the  chapter.  We  have  attempted  to 
make  plain  the  fact  that  the  conscious  content  of  any  single 
moment  is  not  in  itself  a  mere  jumble  of  separate  mental 
states,  but  an  organized  unity  possessing  active  tendencies. 

Origin  and  Growth  of  the  Self. — The  question  of  the  ori- 
gin of  the  self  goes  back  to  that  of  the  origin  of  consciousness 
itself.  We  have  assumed  that  consciousness  was  present 
from  the  very  beginning  of  the  individual's  life.  In  the  very 
earliest  stages  of  life  there  was  no  organization  or  differentia- 
tion of  conscious  experience.  The  little  consciousness  which 
existed  at  that  time  was  probably  only  a  crude  and  unformed 
state  of  awareness.  The' first  experiences  to  take  form  were 
those  coming  from  the  body  and  its  organs  (the  bodily  and 
organic  sensations  and  pains,  such  as  the  cutaneous  and 
muscular  sensations,  the  sensations  arising  in  the  action  of 
the  heart  and  lungs,  together  with  those  of  hunger  and  thirst, 
the  vague  bodily  desires  and  impulses,  and  the  simple  affec- 
tions). Certain  of  these  recurrent  experiences  formed  them- 
selves into  the  nucleus  of  the  self.  Gradually  as  conscious- 


436  PSYCHOLOGY 

ness  of  the  body  and  its  surroundings  became  clear  and  ded- 
nite,  certain  experiences  were  by  their  very  nature  more  inti- 
mate and  personal  than  others  and  these  made  up  the  threads 
which  were  gradually  woven  into  the  inner  strands  of  the  self. 
The  outlines  of  the  self,  which  at  first  included  only  the 
bodily  experiences,  gradually  expand  as  knowledge  of  the 
world  and  our  relation  to  it  increases,  so  that  the  self  comes 
to  embrace  a  larger  and  larger  content.     The  self-feeling 
\  starting  with  our  body  extends  to  our  clothing  and  personal 
1  belongings,  our  family,  our  friends,  our  club,  our  country, 
I  and  many  other  things  which  come  in  time  to  be  identified 
/with  the  self.     The  growing  idea  or  appreciation  of  the  self 
gets  a  social  impress  very  early  in  its  career,  since  the  idea 
of  self  is  determined  largely  by  what  we  think  others  think 
of  us  and  ours.     Our  self-consciousness  is  influenced  to  a  very 
marked  degree  by  this  picture  which  we  imagine  others  form 
of  us — of  our  expressed  thoughts,  likes  and  dislikes,  desires, 
habits,   and  behavior,  of  our  financial  standing  and  social 
position,  our  family,  our  friends,  and  so  on.     This  picture  of 
\\  ourselves  which  we  think  exists  in  the  minds  of  others  is  a 
v  *.a  .   .  \\constant  factor  in  the  contents  of  the  self  and  it  is  implicitly 
ft\A*^   Vpresent  at  all  times.     There  is  some  truth  in  the  popular 
(J^r  /  JfX^statement  that  we  are  what  others  think  of  us.     The  func- 
W  tional  aspects  of  the  self  are  also  influenced  by  the  social 
factor.     For  it  is  a  matter  of  common  observation  that  we 
.jAp*"        tend,  in  what  we  accomplish,  to  measure  up  to  the  ideas 
x  which  others  form  of  our  ability.     The  social  factor  is  a  most 

important  element  in  the  growth  of  the  self. 

No  sketch  of  the  origin  and  growth  of  the  self  is  complete 
which  does  not  consider  the  native  impulses  and  instinctive 
activities  which  are  antecedent  conditions  of  the  self.  They 
not  only  form  the  basis  on  which  the  self  builds,  they  also 
continue  throughout  the  growth  of  the  self.  They  color  and 
modify  it.  The  core  of  the  self  is  the  perpetual  background 
of  organic  sensations,  which  with  the  instinctive  impulses  and 
activities  constitutes  the  beginning  of  the  self.  As  new  ex- 


\o 
<*A* 
(7 V|  .   .\\co 

ft\A*r     vp 


THE    SELF  437 

periences  make  additions  to  the  self  on  the  conscious  side, 
the  formation  of  habits  adds  to  the  reflex  and  instinctive  im- 
pulses of  the  self  on  the  dynamic  side.  The  self  must  be 
considered  not  only  as  a  group  of  conscious  states,  but  also 
as  a  mass  of  habits,  instincts,  tendencies,  and  attitudes. 

Contents  of  the  Self. — Among  the  most  important  factors 
of  the  self  is  the  persistent  group  of  tactual,  kinaesthetic,  and 
organic  sensations,  especially  the  sensations  coming  from  the 
viscera.  In  certain  cases  where  pathological  conditions  have 
changed  the  nature  of  the  visceral  sensations,  there  is  a  notice- 
able change  in  the  patient's  sense  of  personality.  He  feels 
like  a  different  individual.  The  visual  sensations  of  the  ap- 
pearance of  the  body  are  also  a  factor  in  the  contents  of  the 
self.  To  these  elements  we  may  add  our  settled  likes  and 
dislikes.  Even  the  consciousness  of  external  belongings  enters 
into  the  content  of  the  self.  James  has  suggested  that  our 
clothing,  our  stocks  and  bonds,  our  horses  and  bank-accounts, 
our  family  and  friends  belong  in  the  idea  of  self  in  so  far  as 
we  are  conscious  of  them  in  relation  to  our  self.  These  latter 
factors  involve  the  social  element.  It  is  the  consciousness  of 
these  things  as  we  think  they  appear  to  others  which  is  im- 
portant in  our  idea  of  self. 

Thg^  factors  which  contribute  very  largely  to  the  sense  of 
personal  jdentity  and  continuity  are  memory  and  the  organic 
sensa tionsT^ The  fact  that  we  can  reproduce  former  experi- 
ences ancPidentify  them  as  our  own  serves  to  bridge  over 
what  would  otherwise  be  serious  breaks  in  our  personality. 
In  certain  cases  where  the  strands  of  memory  are  broken  off 
altogether  the  sense  of  identity  is  lost.  The  bodily  sensations 
are  fairly  constant  and  continuous  and  so  contribute  a  thread 
of  identity  to  the  experience  of  self.  There  are  other  factors  jQ*4 « 
involved  in  the  consciousness  of  the  self,  but  in  general  j^e  V^ 
may  say  that  the  self-content  is  a  persistent  and 


changing ;  cdrisciouscomplex  in  which  the  elements  just 
tioneoT  are  central  and  consent.     In  normal  individuals  the 
central  self-contents  manifest  no  sudden  changes,  or  abrupt 


438  PSYCHOLOGY 

breaks,  although  there  may  be  considerable  shifting  of  the 
peripheral  contents  corresponding  to  the  different  aspects  of 
the  self  as  manifested  under  different  conditions.1 

Consciousness  of  the  Self. — So  far  we  have  discussed  the 
self  as  a  central  and  persistent  core  of  conscious  content. 
We  must  now  consider  the  manner  in  which  this  self-content 
is  differentiated  and  set  apart  from  the  other  contents  of  the 
mind.     How  does  the  individual  come  to  think  of  certain  of 
his  experiences  in  a  personal  and  self-conscious  way — as  hav- 
ing an  egoistic  reference,  while  other  of  his  experiences  are 
t,  given   a  non-egoistic   reference?     It  is   quite   evident   that 
|  whatever  the  origin  of  "self-feeling"  may  be,  it  is  the  self- 
J  fueling  that  determines  what  conscious  contents  are  set  aside 
to  constitute  the  self.     Before  self-consciousness   arises  no 
selfcan  15e~said  to*  exist,  for  then  all  experiences  are  non- 
personal  and  neutral. 

The  young  child  makes  no  distinction  between  the  self 
and  the  not-self.  Indeed,  he  does  not  distinguish  at  first 
between  objects  and  persons.  Gradually,  however,  it  dawns 
upon  him  that  certain  objects  (persons)  in  his  environment 
react  in  a  peculiar  and  unique  manner,  unlike  the  rest  of  the 
objects  about  him.  Persons  minister  to  his  needs  in  a  way 
that  objects  do  not.  They  wash  and  clothe  and  feed  him. 
They  are  peculiarly  sensitive  to  his  own  acts  and  modes  of 
experience.  At  the  same  time  they  are  capricious  in  their 
movements.  Sometimes  they  come  when  he  cries  and  some- 
times they  do  not.  Moreover,  they  come  and  go  without 
warning.  The  child  is,  therefore,  made  aware  of  a  certain 

(independence  and  self-initiative  in  others  which  is  reflected 
back  to  himself.  He  begins  to  be  conscious  of  his  own  inde- 
pendence of  action.  From  this  point  on  he  both  identifies 
and  contrasts  his  acts  with  the  acts  of  those  other  objects 
which  he  comes  to  know  as  persons.  The  development  of 
self-consciousness  and  the  consciousness  of  others  go  hand 
in  hand.  SeK-consciousness  Js.  therefore,  a  social  product 

1  See  discussion  of  the  self  in  chap.  I,  p.  1 7. 


THE   SELF  439 

brought  about  through  the  contact  with  other  persons  and  is 
the  counterpart  of  Ins  consciousness  of  other  selves.  What 
he  discovers  in  others  he  reads  into  his  own  self,  anoT  what  he 
finds  in  himself  modifies  and  enriches  his  consciousness  of 
other  selves.  What  other  persons  think  him  to  be  (as  mani- 
fested in  their  behavior  toward  him)  is  reflected  into  his  own 
self.  What  he  comes  to  think  of  himself  he  therefore  finds 
in  the  minds  of  others. 

The  Self  and  Sensation. — Having  so  far  regarded  the  self 
as  a  synthesis  of  elements  into  an  organized  whole,  we  may 
now  reverse  the  process  and  consider  the  self  in  relation  to 
some  of  the  discrete  elements  which  constitute  it.  First  of 
all,  we  shall  consider  sensations,  the  simplest  kind  of  con- 
scious content  which  enters  into  the  self.  Hume,  the  great 
champion  of  the  empirical  method,  denied  the  existence  of  a 
self  in  the  form  of  innate  ideas  prior  to  concrete  experiences, 
and  held  sense-perception  to  be  the  source  of  all  conscious 
life.  In  the  beginning,  consciousness  is  simply  a  vague  ac- 
companiment of  bodily  existence,  but  as  sensory  presentations 
multiply,  certain  presentations  break  through  this  primitive 
vagueness  and,  together  with  their  affective  qualities,  they 
are  combined  into  a  mental  organization  which  begins  to 
supplement  the  reflex  and  instinctive  impulses  by  supplying 
new  impulses  of  a  sensory  character.  The  relation  between 
this  beginning  conscious-complex  and  new  sensory  experiences 
is  twofold:  First,  the  discrete  sensory  experiences  furnish 
a  fund^of  new  materiaTwhich  'serves  to  clear  u£__the~o|g!er 
experiences  stored  u^injthe  complex.  SecondlyTthe  self,  or 
organized  complex,  not  pnly_receives  these  separate  sensa- 
tions, but  Jit  goes  out  to  meet  tmTnew  experiences,  selecting 
and  coloring  them  in  accordance  witlLthe  experiences  already 
crystaUized^vnthin__it.  The  self,  therefore,  does  not  grow 
simply  by  accretions  of  new  sensory  experiences,  but  grows 
by  its  own  selective  activity,  in  the  sense  that  it  assimilates 
only  those  sensory  elements  which  harmonize  with  it,  and  for 
which  it  is  already  prepared. 


440  PSYCHOLOGY 

Self  and  Perception. — This  assimilative  character  of  the 
self  is  seen  to  better  advantage  in  perception.  Perception, 
as  we  have  already  seen,  is  an  arousal  of  old  experiences 
within  the  self  by  newly  entering  sensations.  In  perception 
the  self  supplements  any  discrepancy  in  the  new  presentation 
by  supplying  it  with  material  in  keeping  with  its  own  nature. 
The  directive  influence  of  the  organized  complex  of  past  ex- 
perience is  plainly  apparent  in  perception. 

Self  and  Attention. — The  organization  and  growth  of  the 
self  takes  place  very  largely  within  the  field  of  attention. 
This  is  so  because  attention  determines  what  presentations 
enter  consciousness  and  how  they  are  to  combine  with  the 
conscious  elements  already  in  the  mind.  Attention  and  the 
self  are  not,  however,  two  different  factors.  Fundamentally, 
attention  is  the  clearest  and  most  active  portion  of  the  self- 
content.  We  may  agree  to  the  statement  that  attention  is  a 
manifestation  of  the  self  provided  the  metaphysical  assump- 
tion of  a  subject  self  is  not  implied.  For  only  those  things 
enter  consciousness,  arouse  and  hold  attention,  that  possess 
some  elements  of  similarity  to  the  already  assimilated  con- 
tents of  the  self;  or  are  in  some  way  represented  within  the 
self.  In  the  earliest  stages  of  individual  development  the 
self  manifests  itself  through  primary  or  spontaneous  attention 
determined  largely  by  native  and  instinctive  propensities. 
Later  spontaneous  attention  is  a  manifestation  of  a  closely 
knit  organization  of  habitual  experiences  and  acquired  ten- 
dencies. Interwoven  with  these  native  and  acquired  self 
actions  is  secondary  or  voluntary  attention,  determined  by 
a  new  and  consciously  formed  organization  of  experience. 
While  spontaneous  attention  is  an  expression  of  what  the 
Drimary  and  habitual  self  really  is,  voluntary  attention  ex- 
aresses  the  conscious  effort  of  the  self  to  reach  a  higher  stage 
of  development. 

Self  and  Interest. — In  the  chapter  on  attention  we  saw 
that  interest  as  a  psychological  content  is  dependent  upon 
attention  in  that  it  comes  into  existence  only  after  attention 


THE   SELF  441 

has  been  directed  toward  some  object  or  topic  of  thought. 
That  one's  interests  are  a  key  to  his  real  self  is  a  common-t 
place,  but  it  is  even  more  evident  when  we  consider  thatj 
interest  is  aroused  by  those  things  which  readily  catch  and 
hold  the  attention.     We_are  interested  in  the  things  which 
find  affinities  already  within  Ihe  self.     Our  interests,  there-  . 
fore,  represent  both  the  native  and  acquired  characteristics  1 
of  the  self.     As  the  self  develops  they  follow  the  lead  of  vol-  ft 
untary  attention  and  the  simple  affective  states  of  pleasant-  |* 
ness  and  unpleasantness. 

Self  and  Feeling. — There  is  a  tendency  in  certain  quarters 
to  look  upon  the  self  as  a  "feeling-complex,"  with  affection  as 
the  fundamental  background  or  real  unifying  principle  in  the 
self.  Accordingly,  the  real  self  is  considered  to  be  an  organi- 
zation of  affective  life  which  manifests  itself  in  the  apprecia- 
tion of  values  in  the  things  about  us  rather  than  in  the  in- 
tellectual apprehension  of  the  things  themselves.  The  real 
world  is  a  world  of  values  and  the  real  self  is  a  feeling-com- 
plex, and  its  relation  to  the  world  is  an  affective,  not  a  cogni- 
tive one.  However  attractive  this  may  be  as  a  philosophy 
of  the  self,  it  finds  little  psychological  support.  While  it  is 
true  that  the  self  does  manifest  itself  as  "feeling"  or  affec- 
tion, it  is  never  purely  affection  and  nothing  else.  Indeed,  in 
the  author's  opinion,  there  is  no  reason  to  consider  the  affec-  \ 
tive  phase  of  the  self  as  fundamental.  The  self  is  certainly 
never  purely  a  single  phase  of  consciousness.  It  is  just  as 
truly  a  sensation-complex,  an  attention-complex,  a  knowing 
or  willing  complex,  as  it  is  a  "feeling-complex,"  and  each  of 
these  phases  contributes  to  the  more  ultimate  complex — the 
self. 

It  is  true  that  the  strong  feelings  or  emotions  appear  to 
affect  the  self  more  than  any  other  conscious  content.  An 
emotion  seems  to  shake  the  self  to  its  very  foundations.  The 
explanation  of  this  rests  not  in  the  fundamental  or  deep- 
seated  character  of  the  affective  elements,  but  in  the  inhibi- 
tory effect  of  the  emotional  stimulus  upon  the  cognitive  ac- 


442  PSYCHOLOGY 

tivity  of  the  self.  We  are  familiar  with  the  twofold  relation 
between  the  self  and  newly  entering  material.  First,  the  new 
material,  perceptual  or  ideational,  commands  entrance  to  the 
self-content.  Secondly,  the  self-content  goes  forth  to  meet 
the  new  experience,  or,  as  we  have  said  before,  reacts  to  it 
and  determines  by  its  reaction  the  nature  of  the  final  impres- 
sion.  Now,  in  the  case  of  emotions  the  apperceptive  side  of 
/  the  self  is  taken  off  its  guard,  so  to  speak,  and  the  second, 
\  or  efferent  movement  of  the  self,  is  inhibited.  As  a  result, 
the  incoming  impulse  from  the  stimulus  permeates  at  ran- 
dom through,  perhaps,  the  entire  self-content,  causing  a  mass 
of  random  and  diffused  motor  reactions  which  characterize 
the  emotional  seizure.  One  must  not  mistake  the  spectacular 
reactions  of  emotion  for  a  fundamental  movement  of  the  self. 
Really,  emotion  or  feeling  is  not  related  to  the  self,  as  it  is 
sometimes  claimed,  in  any  more  basic  way,  nor  does  it  make 
up  the  contents  of  the  self  any  more  fundamentally  than  do 
cognitive  states  of  consciousness. 

/  Self  and  Will. — We  have  already  called  attention  to  the 
changing  character  of  the  self.  Now  one  aspect  of  the  self 
is  prominent  and  now  another.  The  self  consists  of  a  more 
or  less  changing  complex  of  active  impulses,  desires,  pur- 
poses, thoughts,  feelings,  and  bodily  sensations.  These  are 
projected  against  a  relatively  more  stable  and  invariable 
background-content  made  up  of  habitual  modes  of  thinking 
and  feeling  which,  although  not  always  active,  are  neverthe- 
less potential  in  the  self.  Thus  we  may  distinguish  between 
the  immediate,  or  present  self,  consisting  of  the  contents 
active  at  the  moment,  and  the  more  remote  or  total  self,  in- 
cluding dispositions  laid  down  by  past  experiences  which  are 
drawn  into  the  present  self  in  varying  degrees  at  any  mo- 
ment. Now  the  self  that  determines  action  and  manifests 
itself  in  volition  is  the  present  self.  What  a  man  does  in  a  I 
volitional  way  depends  upon  what  elements  of  his  potential  I 
self  are  active  in  the  present  self  at  the  time  of  his  decisions.  \ 
The  greater  the  number  of  such  elements  active  in  the  present 


THE   SELF  443 

and  temporary  self  the  more  do  his  actions  spring  from  his 
total  self,  and  the  more  do  they  represent  his  will. 

Sleep  and  the  Self. — If  the  self  that  we  know  is  merely 
a  series  of  overlapping  conscious  states,  or  even  a  system  of 
conscious  contents,  how  can  we  explain  the  fact  that  after  the 
interruption  of  sleep  the  self  takes  up  the  threads  of  experi- 
ence just  where  they  were  broken  off?  If  we  assume  the 
existence  of  an  ego,  or  subject  self,  the  interruption  of  sleep 
offers  no  very  difficult  problem.  We  may  then  suppose  that 
the  ego  joins  the  broken  ends  together  and  allows  the  self- 
content  to  go  on  in  a  continuous  stream.  If,  on  the  other 
hand,  we  hold  to  the  empirical  point  of  view,  we  must  explain 
the  continuity  of  the  self  in  terms  of  content  alone.  We  have 
then  no  metaphysical  self  to  join  the  broken  parts  together. 
There  is,  however,  some  reason  to  believe  that  sleep  is  not  I 
an  absolute  break  in  the  conscious  content,  but  a  state  of  I 
reduced  consciousness  in  which  the  higher  synthetic  processes  1 
only  are  suspended,  while  the  bodily  or  organic  sense-impres-  v 
sions  and  perhaps  those  from  some  of  the  special  senses  are 
registered  in  a  lowered  form  of  consciousness.  There  is  some 
empirical  evidence  in  support  of  this  theory.  The  following 
facts  point  to  the  continued  existence  of  some  form  of  con- 
sciousness during  sleep.  In  certain  cases  of  ill-health  we  are 
often  vaguely  aware  of  organic  sensations  or  conditions  which 
pervade  our  sleeping  moments  like  a  wraith.  Although 
asleep,  the  tired  mother  may  hear  every  sound  made  by  her 
sick  child.  Some  persons  are  able  to  judge  the  lapse  of  time 
during  sleep  in  a  remarkably  accurate  manner,  and  are  able 
to  awaken  at  any  moment  they  have  appointed  before  going 
to  sleep.  How  can  such  conditions  exist,  if  during  sleep  there 
is  a  state  of  absolute  unconsciousness?  Locke,  on  the  other 
hand,  held  that  consciousness  may  at  times  wholly  disap- 
pear. If  this  is  true,  we  are  forced  to  assume  the  existence 
of  a  subject  self,  or  else  attribute  the  bridging  of  the  gaps 
in  the  self-content  to  physiological  or  brain  conditions  en- 
tirely. 


444  PSYCHOLOGY 

We  cannot  decide  the  question  for  the  periods  of  deepest 
sleep,  but  in  light  sleep  there  can  be  no  doubt  of  the  fact 
that  a  kind  of  vague  conscious  awareness  is  still  present, 
although  attention  is  almost  completely  dispersed.  The  di- 
rective agency  of  higher  consciousness  becomes  less  and  less 
effective  as  we  pass  into  the  condition  of  sleep,  and  finally  the 
associative  connections  between  presentations  are  so  weak- 
ened that  our  experiences  fail  to  be  synthetized  and,  there- 
fore, cannot  be  recalled.  It  is  just  at  this  point  that  intro- 
spective observation  fails  to  report  anything  beyond  the 
presence  of  a  vague  unorganized  and  unconnected  awareness 
which  defies  description.  As  the  associative  connections 
weaken,  the  associations  become  more  and  more  irrelevant, 
and  the  period  just  preceding  sleep  may  be  marked  by  the 
most  bizarre  images  and  intangible  creations  of  fancy. 

Measured  by  the  intensity  of  stimuli  necessary  to  awaken 
sleeping  subjects,  the  depth  of  sleep  increases  rapidly  during 
the  first  hour,  and  then  becomes  rapidly  lighter  during  the 
next  hour  and  remains  light  until  waking.  The  physiological 
causes  of  sleep  are  supposed  to  be  the  exhaustion  of  the  cell 
substance  in  the  brain,  and  the  presence  of  waste  material, 
or  fatigue  products,  in  the  blood.  The  blood-vessels  in  the 
brain  are  relaxed  and  blood-pressure  is  lowered  during  sleep. 
Likewise  all  the  rest  of  the  vital  processes  are  reduced  in 
/\  ,  activity.  If  the  self  continues  to  exist  during  sleep  it  is  at 
*  lj  best  an  attenuated  ghost  of  the  waking  self. 

Dreams  and  the  Self. — Dreams  mark  those  periods  during 
sleep  when  the  synthetic  and  associative  tendencies  of  con- 
sciousness reassert  themselves.  They  never,  however,  com- 
pletely re-establish  themselves,  for  it  is  quite  evident  from 
the  nature  of  dreams  that  only  a  fragmentary  part  of  the 
self  is  active  in  directing  the  course  of  the  conscious  processes. 
All  kinds  of  strange  associations  are  formed  during  dreams 
as  a  result  of  this  lack  of  control.  Many  conscious  tenden- 
cies which  are  either  too  trivial,  subsidiary,  or  vague  to 
occupy  the  full  attention  of  waking  life,  together  with  those 


THE   SELF  445 

that  are  consciously  inhibited  or  suppressed  for  certain  rea- 
sons, tend  to  seek  expression.  When  the  censorship  of  the 
waking  consciousness  is  lowered  in  sleep,  these  tendencies 
find  an  outlet  in  dreams.  Dreams  may  be  started  by  external 
stimuli,  but  the  dream  consciousness  may  not  be  at  all  in 
keeping  with  the  nature  of  the  stimuli.  Dreams  seem  to 
have  little  regard  for  things  as  they  really  are.  Dreams  which 
occur  shortly  after  falling  asleep  are  often  related  to  the 
things  which  occupied  the  mind  during  the  day  just  closing. 
It  has  also  been  said  that  dreams  of  the  early  morning  antici- 
pate the  events  of  the  coming  day  as  planned  on  the  evening 
before,  and  that  the  dreams  of  deep  sleep  are  representative 
of  the  remote  past. 

It  has  been  claimed  that  the  rate  of  flow  of  conscious 
states  is  very  much  more  rapid  in  dreams  than  it  is  during 
waking  consciousness,  but  as  far  as  the  author  can  determine 
there  is  little  difference  in  this  respect  between  dream  con- 
sciousness and  flights  of  reproductive  imagination  in  waking 
hours. 

The  psychiatrist  Freud  has  proposed  an  interesting  theory 
of  dreams.  He  believes  that  dreams  are  symbolically  repre- 
sentative of  our  secret  wishes  and  desires,  or  ideas,  that  are 
repressed  during  the  waking  life.  When  the  inhibitions  of 
the  waking  self  are  removed,  these  secret  wishes  and  desires 
rise  to  the  surface  and  find  expression  in  our  dreams.  Freud 
holds  that  emotional  experiences  of  youth,  usually  of  a  sexual 
nature,  may  be  suppressed  and  covered  up  to  such  an  extent 
that  they  are  half  forgotten.  They  nevertheless  remain  at 
the  bottom  of  consciousness  as  disturbing  "complexes,"  which 
in  many  cases  are  the  cause  of  hysteria.  These  complexes 
manifest  themselves  in  the  dream-life  of  the  patient,  but  since 
the  dream  does  not  afford  adequate  expression  they  remain 
beneath  the  surface  of  consciousness  as  obsessions  of  which 
he  cannot  rid  himself  until  they  are  brought  out  into  the  full 
light  of  waking  consciousness.  Freud  therefore  analyzes  the 
dreams  of  his  patients  for  the  purpose  of  discovering  the  na- 


446  PSYCHOLOGY 

ture  of  the  "complexes."  He  then  forces  a  complete  expres- 
sion of  the  emotional  experiences  and  relieves  the  mind  of 
its  incubus.  We  cannot  pass  upon  the  correctness  of  Freud's 
theory  of  dreams,  but  it  seems  reasonable  that  impulses  and 
tendencies  that  have  for  various  reasons  been  denied  ex- 
pression in  the  past  should  attempt  to  find  an  outlet 
whenever  a  lapse  occurs  in  the  continuity  of  rational  con- 
sciousness. 

Disturbances  of  the  Self. — We  have  seen  that  the  self  is 
an  association  of  different  conscious  elements  into  a  relatively 
stable  organization  characterized  by  unity  and  identity  of 
experience.  Although  the  contents  of  the  self  are  constantly 
changing,  there  is  in  the  normal  self  no  fundamental  break 
in  its  continuity.  There  is  always  some  associative  link  be- 
tween the  different  self-contents. 

Now,  while  this  statement  is  true  in  the  main,  it  is  not 
absolutely  true,  even  of  the  normal  self.  The  different  parts 
of  the  self  are  not  always  bound  together  into  a  single  stream 
of  consciousness.  It  often  happens  that  different  mental 
processes  take  place  independently  of  each  other,  and  yet 
they  may  be  carried  on  at  the  same  time.  For  instance,  a 
skilful  musician  may  carry  on  an  animated  conversation  with 
one  of  his  auditors  and  at  the  same  time  play  a  difficult 
selection  on  the  piano.  His  consciousness  is  divided  into 
two  parts,  which  are  independent  of  each  other.  His  musical 
consciousness  is  split  off  from  the  rest  of  his  consciousness 
engaged  at  the  time  in  conversation.  He  may  be  unaware 
for  brief  periods  of  his  musical  consciousness,  which  may  in 
the  meantime  lead  him  from  the  particular  selection  he  is 
playing  to  an  entirely  different  selection.  This  splitting  of 
consciousness  into  independent  fragments,  or  the  breaking 
down  of  the  unity  of  the  self  is  technically  known  as  "dis- 
sociation." In  the  normal  self,  however,  dissociation  of  con- 
sciousness is  only  temporary  and  partial,  and  the  momentarily 
severed  parts  are  later  brought  together,  thus  preserving  the 
unity  of  the  self.  In  abnormal  cases,  the  power  of  bringing 


THE   SELF  447 

the  dissociated  parts  together  is  lost.  There  are  many  forms 
of  dissociations  of  consciousness  which  may  be  considered  as 
disturbances  of  the  self.  We  will  consider  very  briefly  some 
of  these  dissociations  of  consciousness  under  the  headings  of 
"mental  blindness,"  "automatic  writing,"  "somnambulism," 
"hypnosis,"  "multiple  personality,"  and  "insanity." 

Mental  or  Psychic  Blindness. — Certain  cases  of  dissocia- 
tion manifest  themselves  in  mental  blindness  or  the  inability 
to  recognize  ordinary  objects  when  plainly  seen.  This  condi- 
tion is  caused  by  disintegration  of  the  associative  connections 
set  up  by  the  different  past  experiences  of  the  objects.  Anal- 
ogous to  this  condition  is  the  inability  to  recognize  and  inter- 
pret sounds  (mental  deafness).  While  a  lesion  in  the  brain 
involving  the  associational  pathways  may  furnish  a  structural 
basis  for  the  dissociations,  it  may  be  brought  about  function- 
ally by  suggestion  in  hypnotized  subjects  or  in  hysterical 
persons.  The  hypnotized  subject  can  be  made  mentally  blind 
to  a  certain  object  in  the  room  through  the  suggestion  of  the 
hypnotist.  If  asked  then  to  name  the  objects  in  the  room,  he 
will  call  off  each  one,  excepting  the  one  involved  in  the  sug- 
gestion. The  consciousness  of  that  object  is  split  off  from 
the  rest  of  his  experience  and  fails  to  connect  with  it.  It  does 
not,  therefore,  make  any  impression  upon  him  at  the  time. 
A'  hysterical  patient  may  also  become  mentally  blind  to  cer- 
tain objects  or  he  may  manifest  various  forms  of  sensory 
anaesthesia.  A  certain  part,  or  all,  of  his  skin  surface  may 
become  apparently  insensitive  to  all  forms  of  stimulation. 
Anaesthetic  patches  were  in  earlier  times  called  "devil's  claw" 
and  were  supposed  to  be  the  mark  of  a  witch.  In  such  cases 
of  "hysterical  anaesthesia"  the  weakened  nervous  condition 
makes  it  possible  for  certain  experiences  to  slip  away  from 
the  unifying  process  of  the  self,  although  they  are  really  pre- 
sented. In  a  perfectly  normal  individual  these  sensory  ex- 
periences are  always  integrated  into  the  self. 

In  these  functional  cases  we  are  probably  not  dealing  with 
absolute  lack  of  awareness  of  the  sensations,  but  with  mental 


448  PSYCHOLOGY 

experiences  which  are  split  off  or  dissociated  from  the  rest  of 
consciousness,  and  which  still  exist  in  a  subconscious  form. 
Sometimes  it  is  possible  to  tap  this  secondary  consciousness 
and  prove  its  existence.  It  is  quite  likely  that  the  supposed 
unconsciousness  in  hysteria  is  not  unconsciousness  but  a  form 
of  dissociated  consciousness  which  fails  to  connect  up  with 
the  rest  of  consciousness. 

Automatic  Writing. — The  phenomenon  of  automatic  writ- 
ing, sometimes  met  with  in  normal  individuals,  but  more 
often  in  cases  of  hysteria,  also  points  to  the  existence  of  men- 
tal states  which  are  dissociated  from  the  self.  If,  while  a 
hysterical  patient  is  deeply  interested  in  reading,  or  engaged 
in  an  animated  conversation,  or  his  attention  held  in  some 
other  way,  a  pencil  is  placed  in  his  hand,  he  will  often  begin 
writing.  If  questions  are  whispered  into  his  ear,  he  may  be 
induced  to  write  answers  to  these  questions  while  his  atten- 
tion is  wholly  absorbed  in  the  reading.  He  is  entirely  uncon- 
scious of  what  his  hand  is  writing,  although  what  he  writes 
may  relate  to  certain  parts  of  his  past  experiences.  Not 
only  is  the  stream  of  his  consciousness  divided  into  two  inde- 
pendent parts,  one  engaged  in  reading  and  the  other  in  writ- 
ing, but  the  writing  consciousness  is  formulating  ideas  con- 
cerning a  part  of  past  experience  which  has  been  previously 
dissociated  from  the  self.  The  two  streams  of  consciousness 
are  ignorant  of  each  other's  existence.  The  self  is  tempo- 
rarily dissociated  into  two  systems  of  consciousness,  each 
engaged  in  two  different  and  independent  activities,  and  in- 
volving two  separate  sets  of  memories.  While  such  dissocia- 
tions are  not  different  in  nature  from  the  ordinary  dissocia- 
tions found  in  a  normal  self,  they  differ  in  the  fact  that  the 
isolated  fragments  of  consciousness  remain  separate  contents 
of  the  self,  and  are  not  unified  as  in  the  case  of  the  normal 
.eelf.  In  fact,  the  presence  of  buried  memories  of  certain  past 
sf  experiences  in  the  subconscious  mental  life  is  now  considered 
\as  the  cause  of  hysteria.  Although  these  memories  are  not 
resuscitated  and  brought  to  the  surface,  they  nevertheless 


THE   SELF  449 

remain  active  as  subconscious  and  suppressed  tendencies,  or 
"complexes,"  which  are  constantly  seeking  the  expression 
which  is  denied  them.  They  exist  only  as  abnormal  distur- 
bances of  the  self.  If  by  any  means  the  physician  is  able  to 
bring  these  suppressed  complexes  to  the  surface  of  the  pa- 
tient's consciousness  and  cause  him  to  give  full  expression  to 
them  and  thereby  unite  the  broken  parts  of  the  self,  the 
symptoms  of  hysteria  disappear.  It  is  for  this  purpose  that 
the  methods  of  psychoanalysis  are  employed.  By  skilful 
questioning  and  probing  through  association  experiments  or 
even  through  hypnosis,  the  patient  may  be  led  to  open  up 
the  disturbing  complexes. 

Somnambulism. — While  the  term  somnambulism  is  popu- 
larly applied  to  sleep-walking,  it  includes  various  forms  of 
dissociated  mental  states  in  which  _the  stream  of  conscious- 
ness, instead  of  being  split  into  two  separate  streams,  both 
going  on  at  the  same  time,  as  in  automatic  writing,  is  broken 
off  abruptly  and  is  replaced  by  an  entirely  different  set  of 
mental  states,  of  which  the  self  has  no  knowledge.  These 
dissociated  mental  states  are  entirely  severed  from  the  normal 
self.  The  somnambulist  may,  while  asleep,  answer  questions, 
carry  on  a  conversation,  get  up  and  hide  a  certain  article  in 
the  room,  or  even  write  down  the  solution  of  a  mathematical 
problem,  and  yet  when  he  awakens  be  totally  ignorant  of 
what  he  has  done.  The  somnambulistic  states  are,  however, 
connected  with  each  other.  This  fact  is  illustrated  by  the 
case  known  to  the  author  of  the  boy  who  found  in  a  somnam- 
bulistic state  a  favorite  toy  that  he  had  hidden  while  in  a 
previous  similar  state.  In  his  waking  condition  between  the 
somnambulisms  he  could  not  find  the  toy  and  had  no  knowl- 
edge of  hiding  it. 

These  milder  forms  of  dissociations  during  sleep  may 
occur  in  highly  nervous  but  otherwise  normal  persons.  In 
hysterical  persons  somnambulism  may  take  place  sponta- 
neously during  waking  hours.  The  trance  of  the  medium, 
the  ecstatic  state  of  the  religious  fanatic  are  usually  somnam- 


450  PSYCHOLOGY 

bulistic  states  which  are  completely  dissociated  from  the 
normal  self. 

The  case  of  ''Irene,"  reported  by  Janet,  is  a  form  of  som- 
nambulism belonging  to  the  border-land  between  sanity  and 
insanity.  Following  a  prolonged  and  extremely  painful  ex- 
perience connected  with  the  death  of  her  mother,  Irene  began 
to  show  symptoms  of  a  mental  breakdown.  Suddenly  while 
engaged  in  her  daily  duties  she  would  stop  short  and  begin 
to  live  through  the  scenes  of  her  mother's  death.  During 
these  seizures  she  appeared  to  be  unconscious  of  what  was 
going  on  about  her.  She  did  not  hear  or  see  those  who  spoke 
to  her.  She  was  oblivious  of  everything  but  her  former 
experiences,  which  she  was  reliving  at  the  time.  The  som- 
nambulism would  end  as  abruptly  as  it  began,  and  the  patient 
would  take  up  whatever  she  had  been  doing  where  she  left 
off,  apparently  unaware  of  the  interruption.  In  a  few  days 
the  same  scenes  would  be  re-enacted.  Janet  found  that  dur- 
ing her  normal  intervals  Irene  could  not  recall  any  of  the 
events  connected  with  her  mother's  death.  These  experiences 
had  become  completely  submerged  in  her  mind.  She  talked 
about  her  mother  without  emotion  and  manifested  a  surpris- 
ing indifference  toward  the  subject  of  her  sickness  and  death. 
In  this  case  we  see  a  complete  dissociation  from  the  normal 
self  of  a  whole  group  of  experiences.  These  experiences  could 
not  be  brought  to  the  surface  of  consciousness,  and  yet  they 
were  present  as  an  isolated  system  of  ideas  in  her  subconscious 
life.  We  shall  find  a  similar  dissociation  of  the  self  in  hyp- 
notic states  and  also  in  cases  of  double  personality.  When 
the  dissociated  system  of  ideas  comes  to  the  surface  and  takes 
the  place  of  the  normal  consciousness  for  any  length  of  time, 
this  system  forms  the  basis  for  the  development  of  a  second 
personality  separate  and  apart  from  the  normal  personality. 

Hypnosis. — Hypnosis  is  an  aberration  of  the  self,  induced 
by  suggestion,  in  which  the  content  of  consciousness  is  nar- 
rowed down  to  the  suggestions  of  the  operator  or  hypnotist. 
To  these  suggestions  the  subject  is  abnormally  sensitive.  In 


THE   SELF  451 

the  hypnotic  state  the  mind  of  the  subject  is  impervious  to 
everything  except  the  thoughts  induced  by  the  hypnotist. 
The  self-initiative  of  the  subject  is  temporarily  in  abeyance, 
and  no  inhibitory  ideas  arise.  Consequently  the  subject  be- 
lieves everything  that  the  hypnotist  tells  him  and  carries  out 
his  requests  mechanically.  If  told  that  in  the  middle  of  the 
room  there  is  a  tree  filled  with  ripe  cherries,  he  will  pick  and 
eat  them  as  though  they  were  real.  He  will  stand  on  his 
head,  swim  in  an  imaginary  pool,  or  fight  imaginary  hornets, 
or  execute  other  trivial  acts  in  accordance  with  suggestions, 
or,  if  the  intimation  is  given  that  he  cannot  move  his  arms, 
he  finds  himself  unable  to  do  so.  In  some  subjects  a  rigid  or 
cjLtalep_tic  condition  of  the  muscles  may  be  induced  by  sug- 
gestion. 

The  first  stages  of  hypnosis  resemble  sleep.  Then  follows 
a  stage  similar  to  somnambulism,  or  sleep-walking,  in  which 
every  idea  put  into  the  mind  is  carried  out  automatically. 
When  the  subject  regains  normal  consciousness,  he  has  no 
recollection  of  what  happened  during  the  state  of  hypnosis. 
There  is  a  complete  dissociation  between  the  normal  self  and 
the  self  of  hypnosis. 

During  hypnosis  there  may  be  marked  changes  in  the 
acuteness  of  the  senses.  Both  hyperaesthesias  and  anaesthe- 
sias may  take  place  under  the  influence  of  suggestions.  The 
hypnotized  person  is  very  sensitive  to  all  forms  of  sensory 
stimuli  coming  from  the  hypnotist  with  whom  he  is  "en  rap- 
port." On  the  other  hand,  certain  sensory  experiences  may 
be  banished  from  consciousness  through  suggestion.  It  is  be- 
cause of  this  fact  that  hypnotism  has  been  employed  to  a 
limited  degree  in  certain  minor  operations  instead  of  the  usual 
anaesthetics.  Its  use  in  surgery  has  not  been  wide-spread 
because  of  the  difficulty  of  control.  The  therapeutic  value  of 
hypnosis  has  be3n  recognized  by  a  few  medical  men,  but  even 
here  its  use  is  very  much  restricted,  although  milder  forms 
of  suggestion  are  very  widely  and  successfully  used  by  physi- 
cians. 


452  PSYCHOLOGY 

The  power  of  inducing  hypnosis  is  not  a  mysterious  or 
occult  gift.  It  consists  merely  in  the  ability  to  attract  and 
hold  the  attention  of  the  subject  and  to  give  suggestions  in 
a  convincing  manner.  Hypnotic  suggestions  are  not  trans- 
mitted to  the  subject  through  any  unusual  channels,  but,  like 
all  other  suggestions  from  without,  they  pass  through  the 
ordinary  sense  pathways.  The  earlier  theory  that  magnetic 
emanations  of  some  kind  are  given  off  by  the  hypnotist  is 
now  discredited. 

No  normal  person  can  be  hypnotized  for  the  first  time 
against  his  will.  By  refusing  to  accept  the  first  suggestions 
offered,  one  may  keep  alive  his  normal  mental  resistance  to 
suggestions.  In  order  to  pass  into  the  state  of  hypnosis  the 
subject  must  voluntarily  give  all  his  attention  and  follow  the 
direction  of  the  operator.  Anything  that  weakens  the  inter- 
nal resistance  of  the  self — fatigue,  drowsiness,  relaxed  mental 
tone,  lack  of  self-confidence,  confidence  in  the  operator — will 
aid  in  bringing  about  hypnosis. 

There  is  a  marked  difference  among  individuals  in  normal 
suggestibility.  Some  take  suggestions  easily,  being  perfectly 
willing  to  follow  the  lead  of  others  and  allow  them  to  assume 
responsibility  for  whatever  is  done.  Others  are  not  subject 
to  the  domination  of  ideas  that  they  themselves  have  not 
passed  upon.  Whether  the  difference  in  the  ease  with  which 
different  individuals  take  hypnotic  suggestion  coincides  with 
this  difference  in  ordinary  suggestibility  we  are  not  at  present 
able  to  determine. 

Posthypnotic  suggestions  are  suggestions  given  during  hyp- 
nosis, to  be  carried  out  after  the  subject  has  regained  nor- 
mal consciousness.  In  many  cases  these  suggestions  are  suc- 
cessful. The  individual  does  not  remember  the  nature  of  the 
suggestion,  but  at  the  time  appointed  he  feels  impelled  with- 
out knowing  why  to  perform  the  suggested  act.  What  really 
happens  is  that  there  is  a  recurrence  of  the  hypnotic  condition 
and  the  deferred  suggestion  is  carried  out  under  its  influence. 

Hypnotic  sleep  may  be  induced  in  various  ways:    By 


THE   SELF  453 

placing  the  subject  in  a  relaxed  and  comfortable  position  and 
reiterating  again  and  again  the  suggestion  that  he  feels  drow- 
siness creeping  over  him,  that  he  will  fall  asleep,  one  may  in 
many  cases  bring  about  the  condition.  Or  the  same  effect 
may  be  produced  by  requiring  the  subject  to  fixate  a  bright 
object  or  a  set  of  rotating  mirrors,  or  by  exposing  him  to  a 
sudden  flash  of  light  or  unexpected  sound,  or  by  allowing 
him  to  listen  to  very  soft  and  monotonous  music  until  the 
attention  is  dispersed  sufficiently  for  suggestions  to  take  effect 
easily.  Some  operators  stroke  the  forehead  or  pass  the  hands 
in  front  of  the  subject's  face  while  suggesting  sleep. 

There  has  been  much  discussion  as  to  whether  hypnosis 
is  a  pathological  condition  or  an  exaggerated  form  of  ordinary 
suggestion.  The  modern  tendency  is  to  consider  it  as  an 
extreme  form  of  suggestion,  to  which  the  self  as  a  whole  is 
unable  to  offer  any  opposition  because  of  its  temporary  dis- 
sociation. In  ordinary  suggestion  the  associational  and  di- 
rective tendencies  of  the  self  are  intact,  i.  e.,  the  will  is  in 
command,  but  in  hypnosis  they  are  not  effective.  The  nor- 
mal interplay  of  motives  is  inhibited  and  the  power  of  mental 
resistance  broken. 

Double  Personality. — In  cases  of  somnambulism,  the  dis- 
sociated systems  of  ideas  are  relatively  simple,  limited  in 
scope,  and  remain  on  the  surface  of  consciousness  only  for 
brief  intervals.  Usually,  too,  the  adaptive  reactions  of  the 
patient  are  crippled  or  entirely  absent,  as  in  trance  states. 
In  some  cases,  however,  the  dissociated  system  of  conscious 
states  becomes  extended  and  comes  to  the  surface  for  long 
periods  of  time,  thus  displacing  the  normal  self.  While  the 
patient  forgets  all  his  past  experiences,  his  name,  his  family 
and  his  friends,  he  may  be  able,  nevertheless,  to  adjust  him- 
self sufficiently  to  his  environment  to  travel  and  even  to  earn 
his  living.  The  dissociated  consciousness  constitutes  a  sec- 
ond personality.  After  this  second  self  has  occupied  the  stage 
for  some  time  the  real  self  may  return  and  resume  command. 
The  patient  is  then  bewildered  and  unable  to  orient  himself, 


454  PSYCHOLOGY 

since  he  has  no  knowledge  of  the  things  which  happened  dur- 
ing the  reign  of  the  secondary  self.  In  some  cases  these  dif- 
ferent selves  may  alternate,  first  one  and  then  the  other 
assuming  control.1 

The  following  account  of  a  representative  case  of  double 
personality  is  taken  from  James's  "Principles  of  Psychology," 
volume  I,  page  391.  The  subject,  the  Reverend  Ansel 
Bourne,  of  Greene,  Rhode  Island,  had  been  brought  up  to 
the  trade  of  a  carpenter,  but  upon  being  converted  from 
atheism  to  Christianity  he  had  become  an  itinerant  preacher. 
Previous  to  the  dissociation  of  the  self,  he  had  been  subject 
to  headaches  and  temporary  fits  of  depression,  and  had  had 
spells  of  unconsciousness  lasting  an  hour  or  less.  He  also 
had  a  partially  anaesthetic  area  on  the  left  thigh.  He  was 
known  in  the  community  as  a  man  of  upright  character. 

"On  January  17,  1887,  he  drew  $551  from  a  bank  in 
Providence,  with  which  to  pay  for  a  certain  lot  of  land  in 
Greene,  paid  certain  bills,  and  got  into  a  Pawtucket  horse- 
car.  This  is  the  last  incident  which  he  remembers.  He  did 
not  return  home  that  day,  and  nothing  was  heard  of  him  for 
two  months.  He  was  published  in  the  papers  as  missing, 
and  foul  play  being  suspected,  the  police  sought  in  vain  his 
whereabouts.  On  the  morning  of  March  14,  however,  at 
Norristown,  Pennsylvania,  a  man  calling  himself  A.  J.  Brown, 
who  had  rented  a  small  shop  six  weeks  previously,  stocked  it 
with  stationery,  confectionery,  fruit,  and  small  articles,  and 
carried  on  his  quiet  trade  without  seeming  to  any  one  un- 
natural or  eccentric,  woke  up  in  a  fright  and  called  in  the 
people  of  the  house  to  tell  him  where  he  was.  He  said  that 
his  name  was  Ansel  Bourne,  that  he  was  entirely  ignorant 
of  Norristown,  that  he  knew  nothing  of  shopkeeping,  and 

1  For  accounts  of  alternating  personalities  see  James's  "Principles  of  Psy- 
chology," vol.  I,  pp.  379-393.  The  case  of  Sally  Beauchamp,  now  quite  well 
known  to  American  readers,  is  described  in  "The  Dissociation  of  a  Personality," 
by  Morton  Prince.  Boris  Sidis  gives  a  very  interesting  case  in  his  book,  "Mul- 
tiple Personality." 


THE   SELF  455 

that  the  last  thing  he  remembered — it  seemed  only  yesterday 
— was  drawing  the  money  from  the  bank,  etc.,  in  Providence. 
He  would  not  believe  that  two  months  had  elapsed.  The 
people  of  the  house  thought  him  insane,  and  so  at  first  did 
Dr.  Louis  H.  Read,  whom  they  called  in  to  see  him.  But  on 
telegraphing  to  Providence  confirmatory  messages  came,  and 
presently  his  nephew,  Mr.  Andrew  Harris,  arrived  on  the 
scene,  made  everything  straight,  and  took  him  home." 

It  should  be  remembered  that  double  personality  mani- 
fests itself  only  in  persons  already  possessing  unstable  patho- 
logical tendencies. 

Insanity. — In  early  times  insanity  was  considered  a  mani- 
festation of  some  supernatural  agency,  and  the  insane  were 
either  revered  as  holy,  or  looked  upon  as  victims  of  some  evil 
spirit.  Hippocrates,  the  father  of  medicine,  was  among  the 
first  to  oppose  this  superstition.  He  believed  that  the  brain 
was  the  organ  of  the  mind  and,  therefore,  that  mental  dis- 
turbances were  due  to  abnormal  conditions  in  the  nervous 
system.  In  modern  times  this  physiological  conception  of 
insanity  has  become  the  prevailing  one.  We  have  come  to 
believe  that  disorders  of  the  mind  are  based  upon  disturbed 
brain  functions.  While  in  many  cases  we  are  able  to  point 
out  the  definite  brain  conditions  which  produce  insanity, 
there  are  other  cases  in  which  we  are  unable,  as  yet,  to  dis- 
cover any  structural  defects  of  the  brain.  This  has  led  to  a 
general  classification  of  insanities  into  structural  and  func- 
tional. The  functional  insanities  are  those  which  reveal  no 
demonstrable  abnormality  of  the  brain.  It  is  thought  by 
some  that  they  are  due  to  purely  psychical  disturbances  of 
the  mind,  while  others  believe  that  further  knowledge  will 
enable  us  to  find  a  physiological  basis  for  them  as  well. 

Even  though  we  may  accept  the  physiological  conception 
of  insanity,  we  can  nevertheless  take  the  purely  psychological 
point  of  view  in  the  study  of  these  abnormal  mental  phenom- 
ena. If  we  take  the  psychological  point  of  view  we  may  ab- 
stract from  the  brain  conditions  which  cause  insanity  and 


456  PSYCHOLOGY 

confine  ourselves  to  a  description  of  the  mental  changes  and 
conditions  which  insanity  exhibits.  The  psychological  con- 
ception, then,  looks  upon  the  phenomena  only  as  states  of 
mind,  and  does  not  attempt  to  go  beyond  the  realm  of  mental 
facts. 

The  actual  cases  of  insanity  exist  in  so  many  varied  forms 
that  the  task  of  classifying  them  is  a  very  difficult  one.  We 
may,  however,  without  going  into  the  matter  very  deeply, 
call  attention  to  the  most  prominent  characteristics  which 
differentiate  the  disturbances  of  the  self.  Insanity  may  be 
defined  as  a  change  or  disturbance  of  the  self  which  renders 
it  incapable  of  functioning  in  a  normal  way.  These  changes 
may  affect  the  self  as  a  whole,  or  they  may  affect  only  a  sin- 
gle part  or  function  of  the  self.  The  former  mental  defect  is 
a  quantitative  change  consisting  in  a  lessening  of  the  general 
mental  capacity  of  the  individual.  He  loses  his  ability  to 
think  and  act  efficiently,  his  intelligence  degenerates  and  he 
becomes  a  being  of  low  and  enfeebled  mentality.  This  con- 
dition is  known  as  dementia.  Its  character  is  best  illustrated 
in  the  decay  or  weakening  of  the  mind  which  accompanies 
extreme  old  age,  when  it  is  spoken  of  as  senile  dementia. 
Dementia,  however,  may  occur  at  any  age,  and  may  mani- 
fest itself  in  various  degrees  of  loss  of  intelligence,  from  a 
slight  lowering  of  mental  power  to  an  almost  complete  loss  of 
mentality.  Dementia  is  acquired.  The  patients  have  been 
at  one  time  persons  of  normal  mental  capacity  but  mental 
decay  has  destroyed  their  powers. 

Besides  these  acquired  forms  of  weak  mentality,  there  are 
other  forms  which  are  not  acquired,  but  congenital.  They 
are  known  asfeeble-mindedness,  and  are  not  usually  considered 
among  the  insanities.  The  feeble-minded  are  born  with  a 
weak  mentality  and  never  attain  a  normal  mental  develop- 
ment. They  are  sometimes  referred  to  as  cases  of  arrested 
mental  development.  Feeble-mindedness  may  exist  in  all 
degrees,  ranging  from  the  lowest  grade  of  mentality  to  a 
condition  which  is  only  slightly  below  normal.  It  has  be- 


THE   SELF  457 

come  customary  to  group  the  feeble-minded  into  three  classes 
— idiots,  imbeciles,  and  morons.  The  idiot  possesses  only  the 
lowest  level  of  intelligence.  He  never  reaches  the  plane  of 
spoken  language  and  is,  therefore,  incapable  of  speech.  He 
can  understand  and  use  simple  gestures,  but  he  is  unable  to 
care  for  himself.  He  requires  the  same  kind  of  oversight 
that  is  given  to  a  very  young  child.  His  mentality  does  not 
exceed  that  of  a  child  of  two  years. 

The  imbecile  possesses  a  slightly  higher  degree  of  intelli- 
gence. He  is  capable  of  understanding  spoken  language  and 
learns  to  talk  himself,  although  he  is  incapable  of  learning  to 
read  and  write  efficiently.  His  knowledge  remains  in  a  very 
elementary  stage  and  never  reaches  the  plane  of  general  ideas. 
His  mental  development  corresponds  to  that  of  children  from 
two  to  eight  years  of  age. 

The  moron  represents  a  still  higher  degree  of  mental  de- 
velopment. In  addition  to  the  acquisition  of  spoken  lan- 
guage he  is  capable  of  learning  to  read  and  write,  and  in 
many  cases  is  able  to  earn  a  living  in  the  simplest  forms  of 
labor.  His  mentality  corresponds  to  that  of  children  from 
eight  to  twelve  years  of  age.  The  mental  inferiority  of  the 
idiot,  the  imbecile,  and  the  moron  is  in  most  cases  congenital, 
and  is  due  to  a  defective  heredity.  The  offspring  of  weak- 
minded  individuals  are  as  a  rule  weak-minded,  also.  In  some 
cases  mental  inferiority  is  due  to  a  pathological  taint  in  the 
parents  who  are  otherwise  normal.  In  a  few  cases  it  is  the 
direct  result  of  such  organic  diseases  as  meningitis  and  scarlet 
fever. 

While  dementia  and  weak-mindedness  are  both  quantita- 
tive defects  of  the  mind  as  a  whole,  there  are  other  alterations 
of  the  self  which  may  be  regarded  as  qualitative  in  nature. 
These  qualitative  changes  are  often  temporary  in  character, 
although  in  some  cases  they  are  more  or  less  permanent. 
With  a  few  exceptions  they  are  regarded  as  recoverable  kinds 
of  insanity.  These  cases  are  marked  by  the  general  psychic 
attitude  which  the  subject  takes  toward  his  experience. 


458  PSYCHOLOGY 

Three  of  the  most  common  attitudes  are  those  of  excitement 
depression,  and  indifference. 

Mania  is  the  most  common  form  of  mental  excitement. 
The  maniac  exhibits  an  abnormal  excitability,  shown  in  vio- 
lent motor  activity  and  rapid  flights  of  ideas.  He  talks  rap- 
idly and  constantly,  jumping  from  one  idea  to  another  with- 
out logical  connection.  He  does  not  carry  out  any  connected 
train  of  thought.  His  movements  are  erratic  and  constant. 
He  occupies  himself  first  with  one  thing  and  then  with  an- 
other, beginning  a  new  task  every  few  minutes.  His  atten- 
tion is  easily  diverted  from  whatever  he  is  doing.  The  ma- 
niac is  usually  in  a  state  of  emotional  excitement.  Generally 
he  is  abnormally  pleased  with  himself  and  everything  about 
him,  although  his  emotional  tone  may  change  to  that  of  irri- 
tability or  violent  anger  at  the  slightest  provocation.  In 
some  extreme  forms  the  emotional  excitement  reaches  the 
highest  pitch.  The  patient  becomes  unmanageable  and  at- 
tacks those  about  him. 

Melancholia  represents  the  opposite  psychic  attitude  of 
depression.  Here  the  patient  is  abnormally  slow  in  thought 
and  speech.  He  sinks  into  a  state  of  deep  misery  and  unhap- 
piness,  from  which  nothing  is  able  to  raise  him.  He  con- 
tinually broods  over  his  real  or  fancied  misfortunes. 

Dementia  pracox  manifests  the  psychic  attitude  of  indif- 
ference. The  patient  lacks  interest  in  the  things  about  him. 
He  pays  no  attention  to  the  things  which  the  normal  person 
is  keenly  alive  to.  He  has  no  hopes,  or  plans,  or  ambition, 
and  is  content  to  remain  in  his  present  condition.  He  is  un- 
tidy and  slovenly  in  his  dress  and  habits.  There  is  a  loss  of 
personal  modesty  due  to  the  lack  of  a  proper  emotional  atti- 
tude. The  stream  of  thought  is  shallow  and  weak,  and  con- 
versation is  incoherent  and  unintelligible.  This  form  of  men- 
tal aberration  appears  in  the  young  usually  about  the  age  of 
puberty,  and  is  progressive.  Absolute  indifference  or  apathy 
is  also  manifest  in  apparent  or  emotional  dementia.  In  these 
cases  the  patient  really  possesses  mental  capacity,  but  be- 


THE    SELF  459 

cause  of  his  abnormal  emotional  indifference  he  does  not  use 
it  in  any  way.  He  sits  in  one  position  for  long  periods  of 
time,  motionless  and  inert,  making  no  effort  whatever,  even 
to  answer  simple  questions  addressed  to  him.  He  shows  no 
interest  in  the  happenings  that  take  place  around  him.  It 
is  impossible  to  arouse  him  from  his  mental  lethargy. 

There  are  other  forms  of  insanity  which  involve  distur- 
bances on  the  intellectual  side  of  the  self.  While  emotional 
changes  accompany  these  intellectual  aberrations,  they  are 
secondary — not  primary,  as  in  the  preceding  cases.  Paranoia, 
for  instance,  is  primarily  an  abnormality  of  the  intellect.  A 
patient  who  apparently  is  normal  in  other  respects  may  be- 
come the  victim  of  some  delusional  idea,  or  may  be  subjected 
to  hallucinations  which  he  is  unable  to  distinguish  from  the 
reality  about  him.  A  false  idea  may  spring  up  in  his  mind 
which  he  is  unable  to  correct.  He  may  believe  that  his  arms 
are  made  of  glass  or  that  some  person  is  persecuting  him  by 
trying  to  poison  him.  For  this  reason  he  may  refuse  to  take 
food.  He  thinks  he  hears  threatening  and  insulting  voices 
which  he  takes  to  be  real,  although  in  other  things  he  seems 
perfectly  rational.  As  a  result  of  these  delusional  and  hallu- 
cinatory ideas  the  patient  loses  his  mental  equilibrium  and 
begins  to  act  strangely.  On  the  other  hand,  the  patient  may 
develop  "delusions  of  grandeur."  He  entertains  an  exag- 
gerated idea  of  his  own  importance  and  frequently  looks  upon 
himself  as  some  celebrated  character,  a  millionaire,  great  in- 
ventor, King,  or  savior  of  the  world,  without  realizing  the 
discrepancies  between  his  real  and  his  fancied  condition. 
Frequently  delusions  of  persecution  and  delusions  of  grandeur 
are  combined.  The  patient  may  think  himself  a  great  in- 
ventor, but  that  certain  persons  are  stealing  his  inventions 
and  conspiring  to  deprive  him  of  proper  and  rightful  recogni- 
tion by  the  world. 

Thus  we  see  that  hallucinations  and  delusions  play  an  im- 
portant and  varied  part  in  the  insanities  involving  the  dis- 
turbances of  the  intellectual  side  of  the  self.  Hallucinations 


f 


460  PSYCHOLOGY 

are  false  perceptions,  through  which  the  patient  becomes 
aware  of  objects  having  no  real  existence.  Auditory  hallu- 
cinations are  very  frequent  among  the  insane.  Some  patients 
are  repeatedly  hearing  voices  which  threaten  or  reproach 
them.  Since  these  are  believed  real,  they  become  serious  dis- 
turbances of  the  self. 

While  hallucinations  are  false  perceptions,  delusions  are 
false  beliefs.  Thus,  if  a  patient  sees,  or  hears,  or  in  any  way 
senses  an  object  which  has  no  objective  existence,  he  has  a 
hallucination,  but  if  he  believes  that  he  is  the  Emperor  of 
China,  or  that  everybody  is  trying  to  put  poison  in  his  food, 
he  has  a  delusion.  A  delusion  may  become  the  basis  for  an 
entirely  new  system  of  view-points  and  reactions.  Everything 
is  changed  and  distorted  to  agree  with  the  delusional  belief. 
An  important  characteristic  of  a  delusion  is  its  perseverance. 
No  argument  is  able  to  dispel  it.  The  most  convincing  proof 
of  its  falsity  is  of  no  avail. 

Obsessions  comprise  another  form  of  intellectual  abnor- 
mality, which,  although  in  a  way  similar  to  delusions,  are  to 
be  distinguished  from  them.  Delusions  carry  with  them  the 
belief  in  their  reality,  while  obsessions  do  not.  An  obsession 
is  the  persistent  presence  of  an  idea,  or  other  psychic  element 
in  consciousness,  in  spite  of  all  efforts  to  banish  it.  A  very 
frequent  obsession  is  the  so-called  "washing  mania,"  in  which 
the  patient  feels  that  his  hands  are  soiled  and  must  be  washed. 
He  knows  that  they  are  not  soiled,  but  he  is  impelled  in  order 
to  rid  himself  of  the  idea  to  wash  his  hands  every  few  minutes 
during  his  waking  hours.  He  is  not  deluded  intellectually, 
i.  e.,  he  does  not  believe  that  his  hands  are  dirty,  but  he  can- 
not get  the  insistent  idea  out  of  his  mind.  Obsessions  exist 
in  various  forms,  from  the  impulsion  to  count  every  crack  in 
the  sidewalk  to  the  insistent  idea  of  killing  one's  own  mother. 
Obsessions  are  found  most  frequently  in  those  cases  of  ner- 
vous debility  (neurasthenia)  which  lie  on  the  border-land  be- 
tween sanity  and  insanity.  In  some  cases  the  overweighting 
of  an  idea  may  be  so  persistent  and  pronounced  as  to  over- 


THE   SELF  461 

balance  the  rational  structure  of  the  self  and  produce  in- 
sanity. 

Hysteria  is  also  a  form  of  self-alteration  which  can  hardly 
be  classed  among  the  insanities,  and  yet,  at  times,  it  ap- 
proaches very  near  if  it  does  not  reach  the  stage  of  insanity. 
It  shows  itself  in  a  highly  exaggerated  impressionability  and 
suggestibility,  in  undue  attention  given  to  the  self,  and  in  an 
abnormal  desire  for  sympathy.  It  also  exhibits  marked  dis- 
turbances of  sensations  and  of  motor  and  glandular  activities. 
Loss  of  sensations  (anaesthesia)  may  appear  in  certain  areas, 
sometimes  to  such  an  extent  that  needles  may  be  thrust  into 
the  skin  without  causing  pain.  The  areas  may  vary  in  size 
from  a  small  patch  to  that  of  the  whole  skin.  In  some  cases 
there  may  be  a  heightened  sensibility  (hyperaesthesia)  and  in 
some  a  distorted  or  perverted  sensibility  (parses thesia) .  The 
fact  that  an  exaggerated  suggestibility  is  a  marked  charac- 
teristic of  hysteria  has  led  to  the  belief  that  it  is  due  to  sub- 
conscious states  of  mind  not  unlike  those  found  in  the  hyp- 
notic state.  This  seems  all  the  more  probable  since  patients 
are  often  cured  merely  by  suggestion.  While  there  is  a  dif- 
ference of  opinion,  some  authorities  look  upon  hysteria  as  a 
functional  disturbance  depending  upon  subconscious  ele- 
ments. The  mental  conditions  which  are  held  to  be  funda- 
mental are  disguised  by  the  facts  that  hysterical  patients 
simulate  the  effects  of  various  organic  diseases.  The  appear- 
ance of  such  organic  disturbances  without  any  structural 
defects  has  made  hysteria  a  very  difficult  condition  to  under- 
stand. 

Freud  and  others  believe  that  hysteria  is  due  to  definite 
emotional  shocks  which,  although  forgotten  or  suppressed, 
and  dissociated  from  the  conscious  self,  still  play  a  disturbing 
subconscious  part  in  the  mental  life  of  the  self.  Such  subcon- 
scious states  are  termed  "complexes."  Embedded  and  held 
in  the  depths  of  the  self,  they  are  thought  to  be  the  cause  of 
vague,  foreboding  fears  and  doubts  which  often  mark  the 
beginning  of  mental  alienation.  The  method  of  treatment 


462  PSYCHOLOGY 

(psychoanalysis)  consists  in  reviving  the  forgotten  or  sup- 
pressed experiences  (complexes)  which  were  the  cause  of  the 
emotional  shocks  and  in  subjecting  them  to  careful  and  ra- 
tional consideration  by  the  patient.  When  this  is  done,  the 
dissociated  fragments  of  experience  are  regained  and  given 
their  proper  value  among  the  other  elements  of  the  self.  The 
subject  is  then  relieved  of  the  disturbing  influences  and  re- 
gains control  of  his  mental  processes  and  the  bodily  symp- 
toms of  organic  disturbances  accompanying  the  hysteria  dis- 
appear. 

Besides  the  so-called  functional  disorders  which  we  have 
just  discussed,  there  are  a  number  of  mental  disorders  usually 
placed  under  the  head  of  structural  psychoses.  Among  them 
are  to  be  noted  general  paresis,  or  softening  of  the  brain, 
choreic  psychoses,  epileptic  psychoses,  and  toxic  psychoses,  all  of 
which  are  due  to  definite  structural  defects  of  the  brain  and 
nervous  system.  Many  of  the  psychic  disturbances  already 
described  also  appear  in  the  structural  insanities  and  need 
no  further  elaboration  in  this  brief  account  of  insanity. 

From  the  foregoing  description  of  the  different  distur- 
bances of  the  self  it  is  evident  that  they  owe  their  character 
to  a  lack  of  harmony  among  the  elements  of  the  self.  Some 
of  the  mental  processes  may  become  overexaggerated  and 
overbalance  the  self-structure.  The  disturbances  may  mani- 
fest themselves  on  the  emotional,  the  volitional,  or  on  the  in- 
tellectual side  of  the  self.  Accordingly,  we  find  the  melan- 
cholias and  emotional  insanities,  obsessions,  and  delusions. 
Conflicts  between  different  systems  of  experience  within  the 
self  may  result  in  dissociations  and  the  formation  of  com- 
plexes which  tend  to  change  the  relations  between  the  parts 
of  the  self  and  destroy  its  unity. 


BIBLIOGRAPHY 

The  books  and  articles  on  psychology  written  since  1894  are  in- 
dexed in  the  annual  Psychological  Index  of  the  Psychological  Review. 
An  extended  bibliography  of  works  on  psychology  can  be  found  in 
Baldwin's  "Dictionary  of  Philosophy  and  Psychology,"  published  in 
1901. 

GENERAL  PSYCHOLOGY 

Angell,  J.  R.     "Psychology."     1905. 

—  "Chapters  from  Modern  Psychology."     1912. 
Baldwin,  J.  Mark.     "The  Story  of  the  Mind."     1898. 

—  "Dictionary  of   Philosophy  and   Psychology."     3  vols.     1901- 
1905. 

Calkins,  Mary  W.     "A  First  Book  in  Psychology."     1910. 

Dunlap,  Knight.     "A  System  of  Psychology."     1912. 

Ebbinghaus,   Hermann.     "Psychology,  an  Elementary  Text-Book." 

(Tr.)     1908. 

Hoffding,  Harald.     "Outlines  of  Psychology."     (Tr.)     1891. 
James,  William.     "The  Principles  of  Psychology."     2  vols.     1890. 

—  "Psychology — Briefer  Course."     1893. 

Judd,  C.  H.     "Psychology,  General  Introduction."     1907. 

Ktilpe,  Oswald.     "Outlines  of  Psychology."     (Tr.)     1895. 

Ladd,  George  T.     "Psychology,  Descriptive  and  Explanatory."    1894. 

McDougall,  William.     "Psychology,  the  Study  of  Behavior."     1912. 

Miinsterberg,  Hugo.     "Psychology,  General  and  Applied."     1914. 

Ogden,  R.  M.     "An  Introduction  to  General  Psychology."     1914. 

Pillsbury,  W.  B.     "The  Fundamentals  of  Psychology."     1916. 

Royce,  Josiah.     "Outlines  of  Psychology."     1903. 

Spencer,  Herbert.     "Principles  of  Psychology."     2  vols.     1895. 

Stout,  G.  F.     "A  Manual  of  Psychology."     1899. 

-  "The  Groundwork  of  Psychology."     1903. 

-  "Analytic  Psychology."     2  vols.     1896. 
Sully,  James.     "Handbook  of  Psychology."     1909. 
Thorndike,  E.  L.     "The  Elements  of  Psychology."     1906. 
Titchener,  E.  B.     "A  Text-Book  of  Psychology."     1911. 

Ward,  James.     "Psychology."     Article  in  Encyclopaedia  Britannica. 
1911. 

463 


464  BIBLIOGRAPHY 

Wundt,  Wilhelm.     "Outlines  of  Psychology."     (Tr.)     1902. 

—  "Human  and  Animal  Psychology."     (Tr.)     1894. 
Yerkes,  R.  M.     "Introduction  to  Psychology."     1911. 

ATTENTION 

Arnold,  Felix.     "Attention  and  Interest."     1910. 

Pillsbury,  W.  B.     "Attention."     1908. 

Ribot,  Th.     "The  Psychology  of  Attention."     (Tr.)     1899. 

Titchener,  E.  B.     "Psychology  of  Feeling  and  Attention."     1908. 

REASONING 

Binet,  Alfred.     "Psychology  of  Reasoning."     (Tr.)     1899. 
Dewey,  John.     "How  We  Think."     1910. 
Miller,  I.  E.     "The  Psychology  of  Thinking."     1909. 
Pillsbury,  W.  B.     "The  Psychology  of  Reasoning."     1910. 

EXPERIMENTAL   PSYCHOLOGY 

Judd,  C.  H.  "Laboratory  Equipment  for  Psychological  Experi- 
ments." 1907. 

"Laboratory  Manual  of  Psychology."     1907. 

Langfeld  and  Allport.  "An  Elementary  Laboratory  Course  in  Psy- 
chology." 1916. 

Myers,  Charles  S.  "A  Text-Book  of  Experimental  Psychology." 
1911. 

Sanford,  E.  C.     "A  Course  in  Experimental  Psychology."     1898. 

Seashore,  C.  E.     "Elementary  Experiments  in  Psychology."     1908. 

Stratton,  G.  M.  "Experimental  Psychology  and  Its  Bearing  upon 
Culture."  1903. 

Titchener,  E.  B.  "Experimental  Psychology."  Four  Parts.  1901- 
1905. 

—  "Experimental  Psychology  of  the  Thought  Processes."     1009. 
Witmer,  Lightner.     "Analytical  Psychology."     1902. 

PHYSIOLOGICAL   PSYCHOLOGY 

Donaldson,  H.  H.     "The  Growth  of  the  Brain."     1900. 

Dunlap,  Knight.     "An  Outline  of  Psychobiology."     1914. 

Edinger,  Ludwig.     "The  Anatomy  of  the  Central  Nervous  System  of 

Man."     (Tr.)     1899. 

Herrick,  C.  J.     "Introduction  to  Neurology."     1915. 
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1911. 
Lickley,  J.  D.     "The  Nervous  System."     1912. 


BIBLIOGRAPHY  465 

Loeb,  Jacques.  "Comparative  Physiology  of  the  Brain  and  Com- 
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McDougall,  William.     "Primer  of  Physiological  Psychology."     1905. 

M'Kendrick  and  Snodgrass.     "The  Physiology  of  the  Senses."     1893. 

Sherrington,  C.  S.  "The  Integrative  Action  of  the  Nervous  System." 
1906. 

Stiles,  P.  G.     "The  Nervous  System  and  Its  Conservation."     1914. 

Villiger,  Emil.     "Brain  and  Spinal  Cord."     (Tr.)     1912. 

Wundt,  Wilhelm.  "Principles  of  Physiological  Psychology."  (Vol.1, 
Tr.)  1910. 

Ziehen,  T.  "Introduction  to  the  Study  of  Physiological  Psychology." 
(Tr.)  1895. 

SOCIAL  PSYCHOLOGY 

Anderson,  B.  M.     "Social  Value."     1911. 

^Baldwin,  J.  Mark.     "Social  and  Ethical  Interpretations  in  Mental 
Development."     1897. 

"The  Individual  and  Society."     191 1.-"*"^ 

x  Boas,  Franz.     "The  Mind  of  Primitive  Man."     1911. 
y'  Brinton,  D.  G.     "The  Basis  of  Social  Relations."     1902. 
^Cooley,  C.  H.     "Human  Nature  and  the  Social  Order."     1902. 
Ellis,  Havelock.     "Studies  in  the  Psychology  of  Sex."     6  vols.     1900- 

1910. 

^Ellwood,  C.  A.     "Sociology  in  Its  Psychological  Aspects."     1912. 
/-Gross,  Hans.     "Criminal  Psychology."     (Tr.)     1911. 
<x  Le  Bon,  Gustave.     "Psychology  of  Peoples."     (Tr.)     1898. 
-"The  Crowd."     (Tr.)     1896. 

—  "The  Psychology  of  Revolution."     (Tr.)     1913. 
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x»Ross,  E.  A.     "Social  Psychology."     1908. 
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466  BIBLIOGRAPHY 


EDUCATIONAL   PSYCHOLOGY 

Bagley,  William  C.     "The  Educative  Process."     1910. 

Colvin  and  Bagley.     "Human  Behavior."     1914. 

Colvin,  S.  S.     "The  Learning  Process."     1912. 

Freeman,  F.  N.     "The  Psychology  of  the  Common  Branches."     1916. 

"Experimental  Education."     1916. 

Home,  H.  H.     "The  Psychological  Principles  of  Education."     1908. 

James,  William.     "Talks  to  Teachers."     1908. 

Judd,  C.  H.     "Psychology  of  High-School  Subjects."     1915. 

"Genetic  Psychology  for  Teachers."     1909. 

Lee,  Joseph.     "Play  in  Education."     1916. 
Meumann,  E.     "Psychology  of  Learning."     (Tr.)     1913. 
Miinsterberg,  Hugo.     "Psychology  and  the  Teacher."     1909. 
Offner,  Max.     "Mental  Fatigue."     (Tr.)     1911. 
Pyle,  W.  H.     "Outlines  of  Educational  Psychology."     1911. 
Rusk,  R.  R.     "Introduction  to  Experimental  Education."     1912. 
Sandiford,  Peter.     "The  Mental  and  Physical  Life  of  School  Chil- 
dren."    1913. 

Schulze,  R.    "Experimental  Psychology  and  Pedagogy."    (Tr.)     1912. 
Starch,  Daniel.     "Experiments  in  Educational  Psychology."     1911. 
Thorndike,  E.  L.     "Education."     1912. 

—  "Educational  Psychology."     3  vols.     1913. 

"Educational  Psychology,  Briefer  Course."     1915. 

CHILD    PSYCHOLOGY 

Baldwin,  J.  Mark.     "Mental  Development  in  the  Child  and  in  the 

Race."     1895. 
Claparede,  Ed.     "Experimental  Pedagogy  and  the  Psychology  of  the 

Child."     (Tr.)     1911. 

Groos,  Karl.     "The  Play  of  Man."     (Tr.)     1001. 
Hall,  G.  Stanley.     "Adolescence."     Two  vols.     1905. 
Kirkpatrick,  E.  A.     ".The  Individual  in  the  Making."     1911. 

—  "Fundamentals  of  Child  Study."     1903. 

Major,  David  R.     "First  Steps  in  Mental  Growth."     1906. 
Montessori,  Maria.     "Pedagogical  Anthropology."     (Tr.)     1913. 

—  "The  Montessori  Method."     (Tr.)     1912. 

Oppenheim,  Nathan.     "The  Development  of  the  Child."     1910. 

Preyer,  W.     "The  Mind  of  the  Child."     (Tr.)     1890. 

Shinn,  Milicent.     "Notes  on  the  Development  of  a  Child."     2  vols. 

1893. 
Stoner,  Winifred.     "Natural  Education."     1914. 


BIBLIOGRAPHY  467 

Sully,     James.     "Studies  of  Childhood."     1895. 
Tracy,  Frederick.     "The  Psychology  of  ChUdhood."     1909. 
Warner,  Francis.     "The  Nervous  System  of  the  Child."     1900. 
-  "The  Study  of  Children."     1899. 

RELIGIOUS   PSYCHOLOGY 

>/<Ames,  E.  S.     "The  Psychology  of  Religious  Experience."     1910. 
T  Coe,  G.  A.     "The  Religion  of  a  Mature  Mind."     1003. 
,/  -   -  "The  Spiritual  Life."  1900. 
'  s  Davenport,  F.  M.     "Primitive  Traits  in  Religious  Revivals."     1906. 

/Durkheim,  Emil.     "Elementary  Forms  of  the  Religious  Life."     (Tr.) 


/•  James,  William.     "Varieties  of  Religious  Experience."     1903. 

King,  Irving.     "The  Development  of  Religion."     1910. 
/•  Leuba,  J.  H.     "A  Psychological  Study  of  Religion."     1912. 
?  McComas,  H.  C.     "The  Psychology  of  Religious  Sects."     1912. 
1   Pratt,  J.  B.     "The  Psychology  of  Religious  Belief."     1907. 
\  Starbuck,  E.  D.     "The  Psychology  of  Religion."     1901. 
.   Stratton,  G.  M.     "  Psychology  of  the  Religious  Life."     1911. 

ESTHETICS 

Gordon,  Kate.     "Esthetics."     1909. 

Hildebrand,  A.     "The  Problems  of  Form  in  Painting  and  Sculpture." 

(Tr.)     1007. 

Puffer,  Ethel.     "Psychology  of  Beauty."     1004. 
Rowland,  Eleanor.     "The  Significance  of  Art."     1913. 

ANIMAL  PSYCHOLOGY 

Forel,  A.     "The  Senses  of  Insects."     1008. 

Groos,  Karl.     "The  Play  of  Animals."     (Tr.)     1898. 

Holmes,  S.  J.     "The  Evolution  of  Animal  Intelligence."     1911. 

—  "Studies  in  Animal  Behavior."     1916. 

Jennings,  H.  S.     "Behavior  of  the  Lower  Organisms."     1906. 
Morgan,  Lloyd.     "Instinct  and  Experience."     1912. 
-"Habit  and  Instinct."     1896. 

—  "Animal  Life  and  Intelligence."     1891. 

—  —  "Introduction  to  Comparative  Psychology."     1894. 
Smith,  E.  M.     "The  Investigation  of  Mind  in  Animals."     1915. 
Thorndike,  E.  L.     "Animal  Intelligence."     1911. 
Washburn,  Margaret.     "The  Animal  Mind."     1908. 
Watson,  John  B.     "Behavior,  an  Introduction  to  Comparative  Psy- 
chology."    1914. 


468  BIBLIOGRAPHY 


ABNORMAL   PSYCHOLOGY 

Barr,  M.  W.  "Mental  Defectives,  Their  History,  Treatment,  and 
Training."  1910. 

Binet  and  Simon.     "  Mentally  Defective  Children."     (Tr.)     1914. 

Brill,  A.  I.     "Psychoanalysis."     1913. 

Burr,  C.  B.     "Psychology  and  Mental  Disease."     1906. 

Dana,  C.  L.     "Text-Book  of  Nervous  Diseases  and  Psychiatry."  1904. 

Freud,  Sigmund.     "The  Interpretation  of  Dreams."     (Tr.)     1913. 

Goddard,  H.  H.  "  Feeble-Mindedness,  Its  Causes  and  Consequences." 
1914. 

Guthrie,  L.  B.     "Functional  Nervous  Disorders  in  Childhood."    1907. 

Hart,  Bernard.     "The  Psychology  of  Insanity."     1914. 

Holmes,  Arthur.     "Backward  Children."     1915. 

Janet,  P.     "The  Major  Symptoms  of  Hysteria."     (Tr.)     1907. 

Jung,  C.  G.     "Psycho-analysis."     1913. 

Kelynack,  T.  N.     (Ed.)     "Defective  Children."     1915. 

Lapage,  C.  P.     "Feeblemindedness  in  Children  of  School  Age."     1911. 

Munsterberg,  Hugo.     "Psychotherapy."     1909. 

Quackenbos,  J.  D.     "Hypnotic  Therapeutics."     1907. 

Rachford,  B.  K.     "Neuroses  of  Childhood."     1895. 

Sherlock,  E.  B.     "The  Feeble-Minded."     1911. 

Shuttleworth  and  Potts.  "Mentally  Deficient  Children,  Their  Treat- 
ment and  Training."  Third  Edition.  1910. 

Sidis  and  Goodhart.     "Multiple  Personality."     1905. 

Tredgold,  A.  F.     "Mental  Deficiency."     1008. 

VOCATIONAL  PSYCHOLOGY 

Bloomfield,  M.     "Readings  in  Vocational  Guidance."     1915. 
Gilbreth,  F.  S.     "Motion  Study."     1911. 

"Psychology  of  Management."     1914. 

Goldmark,  Josephine.     "Fatigue  and  Efficiency."     1912. 
Gowin,  E.  B.     "The  Executive  and  His  Control  of  Men."     1915. 
Hollingworth,  H.  L.     "Vocational  Psychology."     1916. 
Munsterberg,  Hugo.     "Psychology  and  Industrial  Efficiency."     1913. 

^ ' '  B  usiness  Psychology. "     1915. 

_  Scott,  Walter  Dill.    "Increasing  Human  Efficiency  in  Business."    1911. 

"Influencing  Men  in  Business,  the  Psychology  of  Argument  and 

Suggestion."     1911. 
Taylor,  F.  W.     "The  Principles  of  Scientific  Management."     1911. 


BIBLIOGRAPHY  469 


ADVERTISING 

Adams,  H.  F.    "Advertising  and  Its  Mental  Laws."     1916. 
Hollingworth,  H.  L.     "Advertising  and  Selling."     1913. 
Scott,  Walter  Dill.     "The  Theory  of  Advertising."     1903. 
"The  Psychology  of  Advertising."     1908. 

HYPNOTISM 

Binet,  Alfred.     "Alterations  of  Personality."     (Tr.)     1903. 

Bramwell,  J.  M.     "Hypnotism."     1906. 

Moll,  Albert.     "Hypnotism."     1899. 

Prince,  Morton.     "The  Dissociation  of  a  Personality."     1906. 

Sidis,  Boris.     "The  Psychology  of  Suggestion."     1901. 

Wetterstrand,  Otto.     "Hypnotism."     (Tr.)     1902. 

MENTAL  TESTS 

Binet  and  Simon.  "A  Method  of  Measuring  the  Development  of  the 
Intelligence  of  Young  Children."  (Tr.)  1913. 

Franz,  S.  I.     "Handbook  of  Mental  Examination  Methods."     1912. 

Miinsterberg,  Hugo.     "Psychology  and  Industrial  Efficiency."     1913. 

Stern,  William.  "The  Psychological  Methods  of  Testing  Intelli- 
gence." (Tr.)  1914. 

Terman,  L.  M.     "The  Measurement  of  Intelligence."     1916. 

Thorndike,  E.  L.     "Mental  and  Social  Measurements."     1904. 

Whipple,  Guy  M.     "Manual  of  Mental  and  Physical  Tests."     1914. 

Yerkes,  Bridges,  and  Hardwick.  "A  Point  Scale  for  Measuring 
Mental  Ability."  1915. 

HISTORY  OF  PSYCHOLOGY 

Baldwin,  J.  M.     "History  of  Psychology."     2  vols.     1913. 

Brett,  G.  S.     "A  History  of  Psychology."     1912. 

Dessoir,  Max.     "Outlines  of  the  History  of  Psychology."     (Tr.)    1912. 

Hall,  G.  Stanley.     "Founders  of  Modern  Psychology."     1912. 

Klemm,  Otto.     "A  History  of  Psychology."     (Tr.)     1914. 

Rand,  Benjamin.     "The  Classical  Psychologists."     1912. 

Villa,  Guido.     "  Contemporary  Psychology."     (Tr.)     1903. 

MISCELLANEOUS 

Bergson,  Henri.     "Time  and  Free  Will."     (Tr.)     1912. 
Darwin,  Charles.     "The  Expression  of  the  Emotions  in  Man  and  Ani- 
mals."    1872. 
Hobhouse,  L.  T.     "Mind  in  Evolution."     1901. 


470  BIBLIOGRAPHY 

y  Jastrow,  Joseph.     "Character  and  Temperament."     1915. 
ys "The  Qualities  of  Men."     1910. 

"Fact  and  Fable  in  Psychology."     1900. 

/ "The  Subconscious."     1906. 

McDougall,  William.     "Body  and  Mind."     1911. 

Miinsterberg,  Hugo.     "Psychology  and  Social  Sanity."     1914. 
/ "On  the  Witness  Stand."     1908. 

Parmelee,  M.     "The  Science  of  Human  Behavior."     1913. 

Ribot,  Th.     "The  Psychology  of  the  Emotions."     (Tr.)     1897. 

/Seashore,  C.  E.  "Psychology  in  Daily  Life."  1914. 
Sisson,  E.  O.  "The  Essentials  of  Character."  1910. 
Spurzheim,  J.  G.  "Phrenology."  (Revised  from  Second  Edition, 

published  in  1833.)     1908. 

Washburn,  Margaret  F.     "  Movement  and  Mental  Imagery."     1916. 
Watt,  H.  J.     "The  Economy  and  Training  of  Memory."     1911. 

LEADING  PSYCHOLOGICAL  JOURNALS  IN  ENGLISH 

American  Journal  of  Psychology. 

Psychological  Review. 

British  Journal  of  Psychology. 

Mind. 

Journal  of  Philosophy,  Psychology,  and  Scientific  Methods. 

Psychological  Bulletin. 

Archives  of  Psychology. 

Journal  of  Educational  Psychology. 

Journal  of  Animal  Behavior. 

Behavior  Monographs. 

Journal  of  A  bnormal  Psychology. 

Psychological  Monographs. 

Journal  of  Experimental  Psychology. 

Journal  of  Religious  Psychology. 

Journal  of  Applied  Psychology. 


INDEX 


Abnormal  psychology,  as  a  field  of  con< 
sciousness,  3;  disturbances  of  the  self 
in,  446  Jf.;  use  of  association  method  in, 
295  /.,  449;  psychoanalysis  in,  295  /., 
445  /•,  4_6i 

Absolute  pitch,  156,  328 

Abstraction,    in    formation    of    concept, 

302  Jf. 

Accommodation  of  lens,  mechanism  of, 
i66/.,  171,  Fig.  57;  in  presbyopia,  171; 
sensation  from,  in  perception  of  depth, 
221;  a  cause  of  fluctuation  in  percep- 
tion, 73  /. 

Accommodation  of  sense-organs,  in  atten- 
tion, 54,  73/.,  83,  169;  in  vision,  73/., 
i66/.;  in  audition,  73  /.,  146 

Ach,  423 

Achromasia,  189 

Action  theory  of  affection,  368 

Adaptation,  sensory,  96  /. ;  and  intensity, 
99;  in  pain  and  pressure,  96,  124;  in 
temperature,  127;  in  smell,  96,  134;  in 
gustatory  sensation,  141;  in  color  and 
brightness,  1847.;  in  daylight  and  twi- 
light vision,  g6/.,  175,  180 

Adaptation  in  affection,  361,  362 

Adrenalin  secretion  in  emotion,  387 

/Esthetic  experience,  consonance  and  dis- 
sonance in  tones,  162  Jf.,  358;  judgment 
as  evaluation  in,  328/.;  intellectualistic 
view  of  affection  in,  358;  feeling  in, 
373;  as  a  sentiment  or  ideal,  376 

Affection,  Chapter  XVI,  356-376;  refer- 
ence of  consciousness  in,  356;  nature  of, 

356  JT.;  as  an  element  in  consciousness, 
356 /.,  359;  in  feeling,  356,  370  Jf.;  and 
cognition,  356  Jf.,  361  Jf.;  in  attention 
and  interest,    54  /.,   84  /.;  and  pain- 
sensation,    124,   362,   370;  theories  of, 

357  /•;  attributes  of,  360  /.;  qualities 
°f>  357.  359 /•!  tridimensional  theory  of, 
359 /•!  adaptation  in,  361  /.;  and  sensa- 
tion, 357  f.,  361,  366 /.;  and  perception, 
363;  and  ideational  processes,  363;  and 


bodily  expression,  364;  in  conscious- 
ness of  self,  441;  significance  and  func- 
tion of,  368;  neural  basis  of,  366 /.,  382 

After-image,  94  /.;  of  pain  and  pressure, 
123;  visual,  94/.,  185  /.,  191,  193 

Ageusia,  partial,  140 

Alcohol,  effects  of,  in  hallucinations,  211; 
on  imagery,  265 

Alexia,  51,  201 

Alimentary  sensations,  see  Organic  sen- 
sations 

Amnesia,  257 

Anaesthesia,  in  hysteria,  447,  461;  in 
hypnosis,  451 

Analogy,  reasoning  by,  347 

Analysis,  in  formation  of  concept,  302;  in 
judgment,  333  /. 

Angell,  27,  40,  76,  83,  173,  353,  393,  428 

Anger,  384;  organic  sensations  in,  no 

Animal  psychology,  as  a  field  of  con- 
sciousness, 3,  6;  observation  of  behavior 
in,  10,  381,  387,  405  /.;  evolution  of 
nervous  system  and  consciousness,  22, 
354;  acuity  of  smell,  135  /.;  learning  in 
animals,  405  /.;  experimentation  in 
emotion,  381,  387 

Anomalous  color-vision,  190 

Anosmia,  partial,  134 

Aphasia,  motor,  51;  sensory,  51 

Apperception,  199  f.;  judgment  as,  322 
/.,  324;  see  Assimilation 

Appetition,  369 

Apprehension,  330,  340 

Aristotle,  283 

Aristotle's  illusion,  206  /. 

Art  and  imagination,  261  Jf.,  267;  and 
feeling,  371 

Articular  sensations,  104,  214,  214  /.;  see 
Kinaesthetic  sensations 

Assimilation,  in  perception,  199  f.;  in 
illusions,  206  Jf.,  228;  judgment  as, 
322  /.,  324;  and  the  self,  440 

Association,  Chapter  XII,  277-298;  na- 
ture of,  243  Jf.,  277  Jf.;  formation  of, 


471 


472 


INDEX 


278  jf.;  attention  and,  53,  81,  278,  282; 
as  motor  connections,  279;  as  mental 
connections,  279  Jf.;  in  recall,  243  Jf., 
283  Jf.;  laws  of,  283  Jf.;  contiguity,  law 
of,  284 /.;  similarity,  law  of,  28s/.,  350; 
partial  and  total  recall  in,  250 /.,  288 /.; 
falsification  of,  289;  in  judgment,  324, 
328;  in  reasoning,  350;  in  sleep  and 
dreams,  444  /.;  dissociation,  446  jf.; 
tests,  290  Jf.,  449;  neural  basis  of,  49/., 
69,  242,  354  /.,  283,  285,  296  Jf. 

Association  areas  in  cortex,  49 /. 

Association  tests,  290  Jf.,  449 

Associationalists,  274,  277,  283 

Astigmatism,  172 

Asymbolia,  201 

Attention,  Chapter  III,  53-86;  definition 
of,  58;  nature  of  consciousness  in,  53 
Jf.;  structural  characteristics  of,  54, 
56  /.;  functional  characteristics  of,  57 
/.;  forms  of,  58  Jf.;  development  of,  63 
Jf.,  85;  effort  in,  54,  58,  61,  66,  83; 
factors  determining  direction  of,  53  /., 
59  ff-,  67,  85;  interest  and,  54/.,  59/., 
84  /. ;  shifting  of,  70  jf . ;  range  or  span 
of,  76/.;  effort  of,  78  Jf.;  motor  accom- 
paniments of,  8 1  Jf.;  accommodation  of 
sense-organs  in,  54,  73  /.,  83,  169;  and 
perception,  79,  309;  and  association, 
53,  81,  278,  282;  and  memory,  81,  253, 
254;  and  concept,  308,  309;  and  judg- 
ment, 330;  and  feeling,  54/.,  362;  and 
will,  422,  427;  and  the  self,  440;  neural 
basis  of,  67  jf .,  74  /.,  298 

Auditory  area,  48,  152 

Auditory  nerve,  30,  45  /.,  152 

Auditory  sensations,  Chapter  VII,  144- 
165;  classification  of,  109,  144;  stimulus 
of,  152  /.;  end-organ  of,  144  Jf.,  154; 
evolution  of  end-organ,  oo;  brain  areas 
of,  48,  152;  noises,  154;  tones,  155; 
compound  tones,  157;  timbre,  158,  229; 
beats,  159  /.,  165;  combination  tones, 
1 60;  musical  tones,  consonance  and 
dissonance,  162  Jf.;  intensity  of,  161, 
229;  Weber's  law  in,  101;  extensity 
attribute  in,  104,  161,  214  /.;  localiza- 
tion and  projection  of,  228  /.;  in  time 
perception,  233;  and  imagery,  267,  272; 
and  feeling,  361;  theories  of,  150 /.,  162 

Auditory  space  perception,  extensity  at- 
tribute of  auditory  sensations,  103  /., 
161  /.,  216;  localization' and  projection, 
228 /. 


A  ufgabe,  353 

Automatic  work  in  industry,  effect  of,  409 

Automatic  writing,  448 

Autonomic  nervous  system,  31,  Fig.  5 

Aversion,  369 

Awareness,  see  Consciousness,  Attention 

Axon,  32  Jf. 

Bain,  367,  395,  411 

Baldwin,  J.  M.,  5,  271,  411 

Barker,  35,  113,  119 

Beats,  tonal,  physical  basis  of,  i59/.;  in 
dissonance,  159,  165 

Beauchamp,  Sally,  case  of,  454 

Beethoven,  auditory  imagery  in,  267 

Behavior,  and  consciousness,  Chapter 
XVIII,  397-418;  54,  276,  403;  observa- 
tion of,  as  a  method  in  psychology,  3,  7, 
10;  and  attention,  81  Jf.;  and  affection, 
364 /.,  37°;  in  emotion,  377  Jf-,  384  Jf.; 
native  and  acquired,  397;  forms  of, 
398  Jf.;  volitional  activity  in,  401  Jf. 

Belief,  judgment  as,  323  /.,  329 

Berkeley,  219 

Bethe,  34 

Binocular  rivalry,  71  /. 

Binocular  vision,  107,  219  Jf. 

Black,  as  a  sensation,  109,  178  /.;  in 
Helmholtz  theory,  191;  in  Hering 
theory,  192;  see  Visual  sensations 

Blind,  imagery  in,  270,  272 

Blind  spot,  170 

Bodily  expression,  see  Behavior 

Bodily  sensations,  see  Organic  and  Kinjes- 
thetic  sensations 

Book,  353 

Bourne,  Ansel,  case  of,  454 

Brain,  see  Nervous  system 

Brain  areas,  Figs.  28,  29,  30;  cutaneous, 
47,  120;  somassthetic,  120 /.;  pain,  121; 
kinaesthetic,  47,  121;  olfactory,  48,  130; 
gustatory,  48,  138;  auditory,  48,  152; 
visual,  44,  48,  172 /.;  motor,  48;  motor 
speech,  48;  sensory  speech,  50;  visual 
for  written  language,  51;  association, 
49/.,  69,  242,  354 /.;  in  attention,  67/., 
69;  in  perception,  201;  in  imagination, 
239;  in  reasoning,  354;  in  affection,  366, 
368 

Brain  centres,  see  Brain  areas 

Breese,  72 

Brightness  sensations,  see  Visual  sensa- 
tions 

Broca's  centre,  Fig.  jo,  50  /. 


INDEX 


473 


Calkins,  270 

Calm,  as  affection,  359;  cognitive  ele- 
ments in,  360 

Cause  and  effect,  relation  of,  in  associa- 
tion, 280 /.,  287;  in  judgment,  332 

Cerebral  hemispheres,  Figs.  6,  7,  8,  9,  19, 
26,  27;  see  Nervous  system 

Cerebral  nerves,  see  Cranial  nerves 

Character,  and  association,  278;  and 
imagery,  276;  and  the  will,  416,  429 

Chemical  stimuli,  92,  131,  138 

Child  psychology,  2,  10 

Children,  mimetic  movements  in,  390; 
unco-ordinated  random  reactions  in, 
398;  trial  and  error  learning  in,  406; 
conscious  control  of  behavior,  412;  in- 
hibition and  impulse  in,  414;  develop- 
ment of  attention  in,  59,  65;  inattention 
in,  67;  development  of  perception  in, 
77,  204  /.,  321;  de6nition  by,  302; 
sensory  recognition  and  memory  in, 
246;  concrete  imagery  in,  272;  forma- 
tion of  association  in,  277;  falsification 
of  testimony  in,  259,  289;  meaning  and 
reaction,  204 /.,  302,  335,  417;  develop- 
ment of  concept  and  judgment,  335  /.; 
origin  and  growth  of  self,  435  /.,  438; 
functioning  of  frontal  lobes  and  atten- 
tion, 69;  elasticity  of  lens  in,  171 

Chromaesthesia,  271 

Ciaccio,  113 

Circulatory  sensations,  see  Organic  sensa- 
tions 

Clearness,  as  a  characteristic  of  attention, 
S3  Jf.,  65;  in  shifting  of  attention,  72; 
as  an  attribute  of  sensation,  105 

Cochlea,  144  Jf.;  Figs.  49,  50 

Cochlear  fibres,  distribution,  45,  152; 
Fig.  24 

Cognition,  reference  of  consciousness  in, 
356;  sensation  as  fundamental  content 
in,  87,  115,  351;  judgment  as  funda- 
mental activity  in,  329,  336;  and  affec- 
tion, 356  Jf.,  361  /.,  364;  and  feeling, 
329,  370,  372  /.;  and  emotion,  374, 
377  ff-,  383;  and  sentiment,  375 

Cold,  sensation  of,  108,  124;  adaptation 
in,  96,  127;  paradoxical  sensation  of, 
125  /.;  see  Cutaneous  sensation 

Color,  sensations,  see  Visual  sensations 

Color-blindness,  189  /.,  192 

Color  contrast,  186  /.;  in  Hering  theory, 
193 


Color  mixtures,  183  /.;  in  Helmholtz 
theory,  192;  in  Ladd-Franklin  theory, 
195 

Color  pyramid,  182;  Fig.  59 
Color  zones,  188;  Fig.  60;  in  color-blind- 
ness, 189;  Fig.  61;  in  Young  Helmholtz 
theory,  192;  in  Hering  theory,  193;  in 
Ladd-Franklin  theory,  194 
Combination  tones,  i6o/. 
Common  sensation,  pain  as,  123 
Comparative  psychology,  as  method,  6 
Comparison,  in  formation  of  concept,  302; 

judgment  as,  236,  329,  332 
Compensation  in  sensation,  olfactory,  135; 

gustatory,  141 

Complementary  colors,  181,  184;  in  Helm- 
holtz theory,    191;  in  Hering  theory, 
192;  in  Ladd-Franklin  theory,  195 
Complexes,  suppressed  emotional,  295  /., 

445,  449,  461  /. 
Complexes  in  sensation,  143;    in  taste, 

136 

Complication  experiment,  79 
Complication  in  perception,  203,  279 
Compound  tones,  see  Overtones 
Comprehension,  340;  see  Inference 
Conation,  as  an  aspect  of  consciousness, 

419  Jf.;  in  process  of  attention,  58,  84 
Concentration,  as  method  in  memorizing, 

253 

Concept,  Chapter  XIII,  299-320;  nature 
of  the,  301,  305  Jf.;  development  of  the, 
205,  266,  302,  309  /.,  335  /.;  and  per- 
ception, 203,  205,  300,  309;  imagery  in, 
274,  265  /.,  305  /.,  312;  meaning  in, 
274,  307 /.,  312;  intension  and  extension 
of,  308;  psychological  and  scientific, 
303;  general  and  individual,  304;  and 
creative  imagination,  311;  and  judg- 
ment, 335,  338;  and  inference,  341;  and 
language,  312  Jf. 
Conductivity  in  nerve-tissue,  39 
Consciousness,  ultimate  nature  of,  i,  10 
Jf.;  spiritualistic  hypothesis  of,  10  Jf.; 
materialistic  hypothesis  of,  10  Jf.; 
subject-object  nature  of,  12  jf.,  55  /., 
425;  theory  of  origin  of,  410,  435;  as  a 
factor  in  evolution,  369  /.,  410  /.; 
function  of,  64,  75,  205,  234,  259,  275, 
368 /.,  397,  404;  observation  of,  7  jf.; 
elements  in,  87,  352  /.,  356  /.,  420  Jf.; 
and  action,  54,  75  /.,  370,  398  Jf.,  412 
Jf.,  424  /.;  and  attention,  53  Jf.;  in 
learning,  403  Jf.;  determining  tendon- 


474 


INDEX 


ties  in,  s,  424  Jf.;  organization  of,  in  the 
self,  I7/.,  432  Jf.;  and  the  nervous  sys- 
tem, 5,  I4/.,  2  if.,  283:455 

Consonance,  162  Jf. 

Contiguity,  principle  of,  in  association, 
281,  283 1. 

Contrast,  relation  of,  in  association,  280, 
283,  287 

Contrast  in  sensation,  olfactory,  135; 
gustatory,  141;  visual,  i86/. 

Convergence,  168;  sensations  of,  221 

Cope,  411 

Cortical  centres,  see  Brain  areas 

Cramming,  in  learning,  255 

Cranial  nerves,  30;  Fig.  9 

Crime,  association  tests  in  detection  of, 
295 

Curiosity,  384 

Cutaneous  sensations,  Chapter  V,  118- 
129;  classification  of,  108;  end-organs 
of,  118  Jf.;  punctiform  character  of  end- 
organs,  122  Jf.;  evolution  of  sense- 
organs,  91;  brain  areas  of,  47,  i2o/.; 
adaptation  in,  96,  124,  127;  after-images 
in,  95,  123;  and  subcutaneous  sensa- 
tions, I28/.;  and  taste  sensations,  136, 
142,  143;  in  perception  of  heat,  i2S/. 

Czermak,  145 


Darwin,  387  /. 

Day-dreaming,     imagination    in,    264 /.; 

associative  recall  in,  259 
Decision,  in  will,  422 
Deduction,  345  Jf. 
Delirium  tremens,  211 
Delusions,  459 
Dementia,  456 
Dementia  praecox,  458 
Depression,  as  attitude  in  insanity,  458 
De  Quincey,  Thomas,  211 
Descriptive  psychology,  4 
Dexter,  406 
Dewey,  343,  344 
Dichromasia,  349 
Difference-threshold,  intensity  of  stimuli, 

100;  in  pitch,  156 
Difference  tones,  160 
Dissociation,  446  Jf. 
Dissonance,  159,  162  jf. 
Dizziness,  sensation  of,  115,  117 
Dogid,  1 20 

Double  personality,  453 
Drainage  theory  of  association,  297  /. 


Dreams,  nature  of  consciousness  in,  444 
/.;  and  hallucinations,  211;  as  symbols 
of  suppressed  wishes,  296,  444  /. 

Duration,  attribute  of  sensation,  105;  in 
time  perception,  230$.;  and  affection, 
361 /. 

Dynamogenesis,  law  of,  412  Jf. 

Edinger,  28,  29,  47 

Educational  psychology,  2 

Effort,  in  attention,  54,  58,  83,  61,  66; 
feeling  of,  in  will,  425 

Egger,  Victor,  272 

Ego,  12  Jf.,  55;  in  theory  of  will,  420;  as 
directive  tendency,  424  /.;  as  unifying 
principle,  433,  443 

Eigenlicht,  176 

Electrical  stimuli,  92,  138,  176 

Emotions,  Chapter  XVII,  377-396;  na- 
ture of,  374/.,  391 ;  conditions  of,  391  /.; 
significance  of,  394  /.;  feeling  in,  374, 
377;  affective  element  in,  384;  cognitive 
element  in,  377  Jf.;  organic  and  kinaes- 
thetic  sensations  in,  no/.,  377  Jf.,  383; 
and  memory,  395  /.;  instinctive  reac- 
tions in,  317,  377  Jf.,  384  Jf.;  classifica- 
tions of,  395;  and  the  self,  441  /.;  and 
passion,  376;  disturbances  of,  in  insan- 
ity, 458;  James-Lange  theory  of,  377  Jf. 

Epicritic  sensations,  129 

Equilibrium,  sense  of,  115  /.;  in  deaf- 
mutes,  116 

Ethical  experience,  373,  376 

Ethnic  psychology,  3 

Evaluation,  judgment  as,  327 

Excitement,  as  affection,  359;  as  attitude 
in  insanity,  458 

Experimentation,  as  method  in  psychol- 
ogy, 4,  6;  in  attention,  66,  76,  78  Jf.,  80; 
in  kinaesthetic  sensations,  113  Jf.;  in 
cutaneous  sensations,  106,  121  Jf.,  127, 
215,  217;  in  olfactory  sensations,  134 
/.;  in  gustatory  sensations,  138  Jf.;  in 
auditory  sensations,  155,  157,  i59/.; 
in  visual  sensations,  94/.,  184  Jf.,  i88/.; 
in  perception,  200,  207 ;  in  tactile  space, 
215  Jf-;  in  visual  space,  219  Jf.;  in 
auditory  space,  228/.;  in  time,  231  Jf.; 
in  imagination,  269;  in  association, 
290  Jf.,  449;  in  memory,  253  /.;  in  af- 
fection, 364  /.;  in  organic  reactions  in 
emotion,  381,  387;  in  trial-and-error 
method  in  learning,  405 

Extension,  in  concept,  308  /. 


INDEX 


Extensity,  as  an  attribute  of  sensation, 
103  /.;  of  auditory  sensations,  161  /., 
216;  of  visual  sensations,  215,  218;  in 
space  perception,  213  Jf. 

Facial  expressions,  389  /. 
Facilitation,  68 
Fancy,  261,  264 

Far-sightedness,  172 

Fatigue,  and  attention,  67;  memory  in, 
257 

Fear,  384 /.,  392 /.;  organic  sensations  in, 
no 

Fechner,  101 

Feeble-mindedness,  456 

Feelings,  Chapter  XVI,  356-376;  nature 
of,  356,  370 /.;  affection  and  cognition 
m,  356,  370  J/".;  and  organic  sensations, 
no/.,  370,  372;  and  kinaesthetic  sen- 
sations, 417;  classification  of,  371  /.; 
in  attention  and  interest,  54  /.,  84  /.; 
in  intermittent  sensations,  165;  in  con- 
sonance and  dissonance,  164  /.;  of 
familiarity,  204,  245  /.;  and  memory, 
255;  and  judgment,  328;  in  trial-and- 
error  method,  406  /.;  in  mood  and 
temperament,  373  /.;  in  emotion,  374 
/.;  in  sentiments,  375;  and  the  self, 
44i /• 

Fiat,  422 

Flechsig,  49,  50 

Flechsig  centres,  49,  354 

Fluctuation  of  attention,  70  Jf. 

Folk  psychology,  3 

Forgetting,  254  Jf.,  296 

Foveal  vision,  i68/.,  175,  180 

Franz,  129 

Frequency,  in  association,  243,  285 

I'reud,  295,  296,  445,  461 

Frey,  von,  126 

Friendship,  375 

Fry,  229 

Functional  psychology,  5 

Gallon,  267,  269,  271,  273 
Gallon  whistle,  155 
Galvanometer,  365 
Gegenbaur,  39 
Generalization,  302  jf. 
Generic  image,  306  /. 
Genetic  psychology,  2,  4 
Gesture  language,  314  jf. 
Global  method,  253 


475 

Gray,  in  Hering  theory,  193;  in  Ladd- 
Franklin  theory,  I94/. 

Greeff,  169 

Grief,  emotion  of,  394 

Gustatory  sensations,  Chapter  VI,  136- 
143;  classification  of,  109,  139;  end- 
organ  of,  137,  139;  brain  areas  of,  48, 
130;  retardation  of,  140;  imagery  of, 
268;  affection  and,  361;  and  mimetic 
movements  in  emotion,  389  /. 

Habit,  nature  of,  400  /.;  and  volitional 
action,  401  Jf.;  law  of,  in  recall,  243;  as 
organic  memory,  248  /.;  imagery  and, 
275;  and  association,  279;  neural  basis 
of,  279,  400 

Hallucinations,  and  perception,  203,  210 
Jf.;  neural  basis  of,  212;  in  insanity,  459 

Hardesty,  151 

Hay  craft,  132 

Hearing,  see  Auditory  sensations 

Heat,  perception  of,  125  Jf. 

Hegel,  358 

Hdmholtz,  150,  155,  165,  171,  191,  338,  339 

Hemianopsia,  174 

Hensen,  151 

Hering,  192,  224 

Hering  color  theory,  192  Jf. 

Hippocrates,  455 

Hobhouse,  404 

Howell,  44,  145 

Human  adult  psychology,  2 

Hume,  336,  439 

Hunger,  92,  109,  no;  as  a  feeling,  370 

Hyperaesthesia,  in  hypnosis,  451;  in  hys- 
teria, 461 

Hypermnesia,  258 

Hyperopia,  172 

Hypnosis,  450 /.;  hallucinations  in,  211; 
mental  blindness  in,  447;  and  will,  452 
/.;  suggestion  in,  450  Jf. 

Hypothesis,  in  science,  n 

Hysteria,  295,  445,  448,  461;  association 
method  in,  295;  psychoanalysis  in, 
296,  445,  461;  mental  blindness  and 
sensory  anaesthesia,  447;  automatic 
writing  in,  448;  somnambulism  in,  449; 
suggestion  in,  461 

Idea,  274 

Ideals,  376 

Ideogram,  315 

Ideo-motor  reactions,  398,  401 

Idiot,  457 


476 


INDEX 


Illusions,  and  perception,  203;  and  hal- 
lucinations, 203,  210;  causes  of,  206  Jf.; 
of  space,  222  _ff.,  225  f.;  of  movement, 
207 /.;  in  memory,  258;  neural  basis  of, 
212 

Imageless  thought,  351  /.;  and  volition, 
424 

Imagery,  2387.;  types  of,  266  jj.\  concrete 
and  symbolic,  271  /.,  305,  312  $.;  in- 
dividual differences  in,  267,  272;  in 
synssthesia,  270;  in  sleep  and  dreams, 
444 /.;  in  concept,  305  /.;  in  thinking, 
299,  320,  351  f.;  in  consciousness  of  re- 
lation, 351  /.,  353;  in  volitional  action, 

4°3 

Imagination,  Chapter  XI,  260-276;  and 
sensation,  238,  262,  266,  274;  and  per- 

.  ception,  203,  238 /.,  262,  268,  274;  and 
memory,  240,  260;  and  feeling,  370;  and 
affection,  363,  366;  and  thinking,  209, 
351  /.;  reproductive,  240,  261  f.;  pro- 
ductive, 261  .#.;  development  of,  272 /.; 
training  of,  2?4/.;  and  behavior,  64,  275 
/.;  function  of,  64,  234,  275;  neural  basis 
of,  50,  2387. 

Imbecile,  457 

Imitation,  384;  in  gesture  language,  314; 
in  early  writing,  315;  in  spoken  lan- 
guage, 316 

Impulse,  motor,  in  consciousness,  82,  276, 
296,  402,  412  JT.,  419 

Inattention,  67 

Indifference,  as  attitude  in  insanity,  458 

Individual  differences,  in  olfactory  sen- 
sations, 134;  in  taste,  142;  in  pitch  dis- 
crimination, 156;  in  retention,  241;  in 
memory,  249 /.;  in  imagery  types,  272, 
267;  in  temperament,  374;  in  suggesti- 
bility, 452 

Individual  psychology,  2 

Induction,  345  f. 

Inference,  338  f.;  inductive  and  deduc- 
tive, 345  JT.;  and  perception,  339;  and 
concept,  341;  and  judgment,  334,  338, 
340;  in  thinking  process,  300,  338  ff.,  344 

Inhibition,  in  action  of  nervous  centres, 
68;  retroactive,  282;  and  affection,  367; 
and  impulse,  414;  defective  in  impulsive 
will,  428;  in  hypnosis,  451  JT. 

Innervation,  feeling  of,  426 

Insanity,  455;  classification  of,  455;  and 
hallucinations,  210;  association  tests  in, 
291,  295;  psychoanalysis,  2957.,  445 
Jf.,  461;  neural  basis  of,  455,  462 


Inspiration,  and  imagination,  264 

Instinctive  reactions,  397  /.;  theories  of 
origin,  410 /.;  in  emotion,  378,  384  /.; 
in  development  of  self,  436;  neural  basis 
of,  375,  386 /. 

Integration,  principle  of,  280 

Intension,  of  concepts,  308 

Intensity,  as  attribute  of  sensation,  98  JF. ; 
distinguished  from  vividness,  105;  of 
auditory  sensations,  161,  229;  of  visual 
sensations,  180;  and  affection,  360  /., 
368;  and  pain,  99,  362;  and  attention, 
65 ;  Weber's  law  in,  101  /. 

Intention  or  purpose,  in  volitional  activ- 
ity, 402 

Interest,  and  attention,  54/.,  59/.,  84/.; 
native  and  acquired,  85 ;  feeling  element 
in,  54 /.,  84/.;  and  memory,  255;  and 
association,  281;  and  the  self,  427,  440 

Interjectional  theory,  of  language  origin, 
3i8 

Intertone,  160 

Introspection,  as  scientific  observation, 
7  JT;  in  attention,  56,  82/.;  in  sensation, 
87 /.,  97,  102,  104,  in,  113,  115,  117, 
118,  124,  136,  144,  154,  157;  in  per- 
ception, 87/.,  210;  in  affection  and  feel- 
ing. 357.  372;  in  judgment,  322,  326, 
336;  in  consciousness  of  relation,  336; 
in  imageless  thought,  352/.;  in  volition, 
420,  423,  425;  in  sleep,  444 

Invention,  and  imagination,  261  /. 

Involuntary  attention,  60 

Involuntary  movements,  in  attention,  8?: 
in  affection,  364  /. 

Irene,  case  of,  450 

Irritability  of  nerve-tissue,  39,  89 

James,  12,  87,  104,  173,  208,  210,  214,  216, 
219,  240,  249,  250,  252,  265,  267,  286, 
292,  300,  336,  35°,  377,  379,  383,  384, 
386,  410,  422,  424,  426,  427,  428,  434, 

437,  454 

James-Lange  theory  of  emotions,  377  JT. 
Janet,  450 
Jastrow,  257 

Jastrow's  illusion  of  area,  225,  226 
Jost's  law,  282 
Joy,  emotion  of,  393 
Judd,  47,  286 
Judgment,  Chapter  XIV,  321-337;  nature 

of,   321  JF.;   in   the   thinking   process, 

300,  335  Jf.;  as  apperception,  322,  324; 

as  belief,    323,    329;   as   ascription   of 


INDEX 


meaning,  324,  329;  as  comparison,  326, 
329,  332;  as  evaluation,  327,  330; -de- 
velopment of,  335;  analysis  and  syn- 
thesis in,  333  /.;  logical  and  psycho- 
logical, 321  Jf.,  330 /.;  kinds  of,  331  /.; 
and  perception,  203,  204,  321  /.,  325, 
327,  332,  334,  337;  and  recognition,  204; 
and  feeling,  328;  and  association,  324, 
328;  and  concept,  335,  338;  and  infer- 
ence, 334,  337,  338  /.,  340 
lung,  295,  296 

Kant,  322,  323,  434 

Kiesow,  140 

Kinaesthetic  sensations,  Chapter  V,  112- 
117;  classification  of,  108;  observation 
of,  113;  stimuli  of,  112,  116;  sense- 
organs  of,  112,  116,  128;  brain  areas 
of,  47,  121,  152;  as  effort  in  attention 
and  will,  54,  55,  58,  82  Jf.,  425;  in  in- 
nervation,  426;  in  touch,  118;  in  space 
perception,  114  /.,  213  Jf.;  local  sign  in, 
214  Jf.;  in  locomotor  ataxia,  401,  423; 
in  time  perception,  232  /.;  imagery  of, 
267  Jf.,  272,  421 /.;  as  cues  in  habit,  401; 
in  consciousness  of  relation,  351; 
imagery  of,  in  volitional  action,  421  /.; 
in  feeling,  360,  416 /.;  in  emotion,  374, 
377  JF -i  383,  417;  in  consciousness  of  self, 
18,  112,  426,  435,  437 

Kolliker,  33 

Krause,  end-organ  of,  Fig.  43,  120 

Ladd  and  Wood-worth,  28,  29,  31,  34,  35,  39, 
46,  102,  103,  113,  117,  118,  119,  150, 
171,  209,  298. 

Ladd-Franklin    theory    of    color   vision, 

i94/- 
Lange,  377 

Language,  and  introspective  method,  8/.; 
function  of,  313;  development  of,  314; 
origin  of  spoken,  316;  imagery  in,  272, 
3 1 2  Jf . ;  and  concept,  312;  and  judgment, 
321  Jf.;  and  thought,  320;  in  feeble- 
minded, 457;  brain  centres  involved 
in,  Si 

Lapsed  intelligence  theory,  411 
Latent  period,  in  perception,  79,  200 
Learning,    and    memory,    253    /.,    255; 
through  trial  and  error,    405  Jf.,    420; 
through  conscious  control,  403  Jf.,  420  /. ; 
in  animals,  405 
i     Lehmann,  368 
Linnaus,  132 


Lip ps,  227 

Lipps's  parallels,  224 

Literature,  and  imagination,  261  /.;  and 

feeling,  371 

Local  sign,  106,  122,  213  Jf. 
Localization,  in  space  perception,  216  Jf., 

228  Jf. 

Localization,  of  function  in  the  train,  47  Jf. 
Locke,  12,  240,  306,  342,  443 
Locomotor  ataxia,  401,  423 
Logic,  formal,  in  practical  thinking,  345 

Jf.;  in  formation  of  concept,  302  /.;  in 

judgment,  321  Jf.,  330 /.;  in  inference, 

345  J^;  syllogism  in,  349 
Logical  memories,  250  /. 
Logical  present,  233 
Love,  as  sentiment  and  emotion,  375 

McDougall,  297 

Mania,  458 

Masson's  disc,  Fig.  36,  72  Jf. 

Materialistic  hypothesis  of  consciousness, 
10  Jf. 

Mathematics  and  imagination,  261  /. 

Meaning,  consciousness  of,  in  perception, 
203  /.,  321,  325,  339;  and  image,  266, 
274,  305,  307,  312,  3S3!  in  concept,  307 
Jf.;  in  judgment,  324 /.,  329  Jf.;  language 
and,  312  Jf. 

Measurement,  as  method  in  psychology, 
4,  8/.;  in  attention,  66,  76,  78 /.,  80; 
in  intensity  of  sensation,  99  Jf.,  122;  in 
two-point  threshold,  106,  122;  in  ol- 
factory sensations,  134;  limits  of  tonal 
range,  155;  tonal  discrimination,  156; 
fields  of  retinal  color  zones,  188;  of 
association  time,  292;  of  learning  and 
memory,  254;  see  Experimentation 

Mechanical  stimuli,  92,  138,  152  /.,  176 

Meissner's  corpuscle,  91,  119,  Fig.  41 

Melancholia,  458 

Memory,  organic,  248  /. 

Memory,  Chapter  X,  238-259;  nature  of, 
240  Jf.;  function  of,  259;  and  imagina- 
tion, 238  Jf.,  260;  stages,  241;  retention, 
241,  252;  recall,  241  //.,  250  /.,  253; 
recognition,  241,  245  Jf.,  258,  260;  logical 
and  rote,  250  /. ;  methods  of  memoriz- 
ing, 253  /.;  and  forgetting,  254  Jf.; 
training  of,  252;  individual  difference 
in,  241,  249 /.;  defects  of,  257 /.;  atten- 
tion and,  81,  253 /.;  and  affection,  363 
/.;  and  feeling,  255,  370;  and  emotions, 
395  /-I  °f  time  periods,  236;  and  self, 


478 


INDEX 


437;  neural  basis  of,  50,  238/.,  241,  252, 
256 

Mendelejeff' s  groups,  and  olfactory 
stimuli,  131 

Mental  blindness,  51,  201,  447 

Mental  deafness,  51,  152,  201,  447 

Meyer  experiment,  187 

Meynert,  368 

Michotte,  423 

Mimetic  movements,  in  emotion,  390 

Mind,  16  Jf.,  55  /.,  241 

Mind- readers,  82,  415 

Modality  in  sensation,  98 

Mood,  373 

More,  L.  T.,  229 

Moron,  457 

Mosso,  387 

Motor  activity,  and  consciousness,  402 
Jf.,  412  Jf.,  416  Jf.,  422 

Motor  aphasia,  51 

Motor  areas  in  cortex,  48,  Figs.  28,  29,  30 

Motor  attitude,  in  consciousness  of  re- 
lation, 351 

Motor  tracts,  4o/.,  Figs.  18,  21 

Movement,  compensatory,  in  disturbed 
equilibrium,  115 

Movement,  sensations  of,  see  Kinxsthetic 
sensations 

Miiller-Lyer  circle,  225,  226 

Miiller-Lyer  illusion,  209,  226 /. 

Miinsterberg,  105,  289,  295,  368,  382, 
424 

Muscular  sensations,  see  Kinaesthetic  sen- 
sations 

Musical  tones,  156,  162  Jf. 

Myers,  229 

Myopia,  172 

Nausea,  109,  no,  133 

Near-sightedness,  172 

Nerve-cell,  32  Jf . 

Nerve  impulse,  36  jf.,  89 

Nervous  system,  Chapter  II,  21-52;  and 
consciousness,  5,  14  /.,  21  /.,  283,  455; 
development  of,  22  jf.;  gross  structure 
of,  26  jf.;  neurones  and  connections  in, 
32  Jf.;  localization  of  function  in,  47  Jf.; 
organic  memory  in,  248  /.;  law  of  re- 
gression in,  256;  see  Neural  basis 

Neural  basis  of,  consciousness,  5,  14  /., 
21  JT.,  283,  445;  attention,  67  Jf.,  74  /., 
298;  sensation,  88  jf.,  98  /.,  104;  or- 
ganic sensations,  91  /.,  in;  kinaesthetic 
sensations,  47,  112,  116,  121,  128,  152; 


cutaneous  sensations,  47,  n8/.,  i2o/., 
123 /.,  126  Jf.;  olfactory,  48,  130,  134; 
gustatory,  48,  130,  134,  137  /.,  139  Jf.; 
auditory,  48,  144  Jf.,  152  /.,  162;  visual, 
44,  48,  166  Jf.,  172  Jf.,  176  /.,  188  Jf.; 
perception,  48,  68,  201  /.,  212,  239;  il- 
lusion, 212;  hallucination,  212;  associ- 
ation, 49  /.,  69,  242,  283,  285,  296  Jf., 
354/.;  memory,  50,  2387.,  241,  252,  256; 
retention,  241,  252,  256;  recall,  241  /.; 
imagination,  50,  238 /.;  reasoning,  354; 
affection,  3667.,  382;  impulse,  415,  418; 
instinctive  reactions,  375,  386/.;  habit, 
279,  400;  insanity,  455,  462 

Neurasthenia,  295,  460 

Neurology,  6 

Neurone,  32  Jf. 

Noises,  109,  144,  154;  see  Auditory  sensa- 
tions 

Non-voluntary  attention,  59;  and  inter- 
est, 85 

Number  forms,  271 

Nystagmus,  190 

Observation,  method  in  psychology,  7  Jf.; 
see  Introspection,  Behavior,  Experimen- 
tation 

Obsessions,  460 

Octave,  in  musical  scale,  162;  as  con- 
sonant interval,  165 

Oehrn,  66 

Oehnvall,  140 

Ogden,  424 

Olfactory  area  in  cortex,  48,  130 

Olfactory  sensations,  Chapter  VI,  130- 
136;  classification  of,  109,  132;  stimulus 
of,  130 /.;  end-organ  of,  130,  134;  brain 
centres,  48,  130;  adaptation,  96,  134; 
threshold,  133;  extensity  attribute  in, 
104,  215;  fusions,  contrast,  compensa- 
tion, 135;  and  gustatory  sensations, 
136,  143;  and  kinaesthetic  sensations, 
416;  and  imagery  of,  268;  and  affection, 
361;  and  feeling,  135 

Onomatopoetic  tendency  in  language, 
273,  3i6Jf. 

Ontogenesis,  4 

Opium,  effect  of,  in  hallucinations,  211; 
on  imagination,  265 

Optic  chiasma,  44,  172  /. 

Optic  disc,  170 

Optic  nerve,  30,  44,  169,  172  Jf. 

Organ  of  Corti,  148  Jf.,  Fig.  51 

Organic  memory,  248  /. 


INDEX 


Organic  sensations,  Chapter  V,  110-112; 
classification  of,  108,  no/.;  stimuli  of, 
91  /.,  in;  end-organs  of,  in;  localiza- 
tion of,  112;  in  time  perception,  231, 
233.  235 /.;  and  affection,  258,  360;  in 
feeling  and  emotion,  no  /.,  370,  372 
I-,  377  ff-,  383;  in  sleep,  443;  and  self, 
18,  112,  435,  437 

Overtones,  physical  basis  of,  157;  in 
timbre,  158;  in  consonance  and  dis- 
sonance, 165;  as  aid  in  localization  of 
sound,  229 

Pacinian  corpuscles,  112,  120 

Pain-sensations,  122  /.;  distinguished  from 
affection,  124,  362;  and  feeling,  370; 
and  intensity  of  sensations,  99,  362 

Paradoxical  sensation  of  cold,  125 

Parallax,  222  • 

Paramnesia,  258 

Paranoia,  459 

Partial  recall,  251,  288 /. 

Partial  tones,  see  Overtones 

Passion,  376 

Passive  attention,  61 

Pathognomic  theory,  of  origin  of  spoken 
language,  318 

Perception,  Chapter  IX,  197-237;  and 
sensation,  197  f.,  204;  complication  in, 
203,  279;  recognition  in,  200,  203  /., 
246  /.,  321,  337;  meaning  in,  197  jff., 
2°3  /-,  321,  325.  339;  illusions  in,  203, 
206  jff.,  212;  hallucinations  and,  203, 
210  f.;  function  of,  205;  development 
of,  77,  202,  204 /.,  321;  units  of,  in  at- 
tention, 77;  latent  period  in,  79,  200; 
and  imagination,  203,  238  /.,  262,  266 
/.,  268 /.,  274;  and  association,  278 /.; 
and  concept,  203,  205,  300,  309;  and 
judgment,  203 /.,  321  /.,  325,  327,  332, 
334.  337;  and  inference,  338  /.;  and 
thinking,  299 /.;  and  affection,  363;  in 
emotion,  374,  383;  and  motor  reaction, 
202,  204,  302,  417;  and  the  self,  440; 
neural  basis  of,  48,  68,  201  /.,  212,  239; 
of  tactual  space,  103  /.,  106,  122,  213 
f.\  of  visual  space,  103 /.,  106,  114,  172, 
212  Jf.;  of  auditory  space,  103 /.,  i6i/., 
216,  228 /.;  of  time,  105,  230$. 

Perimeter,  188 

Perspective,  in  visual  space  perception, 

221 /. 

Phosphenes,  176 
Photic  stimuli,  92,  176 


Phylogenesis,  4 

Physiological  basis,  see  Neural  basis 

Physiological  psychology,  5 

Physiological  reactions,  398 

Physiological  stimuli,  in  organic  sensa- 
tions, 91,  108,  ii i;  in  vision,  176 

Physiological  zero  in  temperature  sensa- 
tions, 124  jf. 

Pillsbury,  82,  199,  334,  120 

Play,  384 

Pleasantness,  see  Affection 

Plethysmograph,  364 

Pneumograph,  364 

Poggendorff  figure,  225 

Prejudice,  342 

Presbyopia,  171 

Pressure  sensations,  see  Cutaneous  sensa- 
tions 

Primitive  peoples,  language  and  writing, 

315 /• 

Prince,  454 
Projection,  in  space  perception,   216  f., 

228jf. 

Protopathic  sensations,  128 

Psychic  blindness,  51,  201,  447 

Psychical  present,  232  /. 

Psychoanalysis,  295,  445,  449,  461 

Psychology,  definition  of,  i;  fields  of,  2; 
methods  of,  2;  scientific  method  in,  7 
jf.;  data  of,  differentiated,  i,  10  jf.,  13 
f.,  92/.,  322,  419,  425,  429 /.,  434 

Psychophysics,  6 

Pupillary  reflex,  170 

Purkinje  phenomenon,  180,  194 

Purkinje's  network,  168 

Quain,  118,  138 

Quality,  as  an  attribute  of  sensation,  97 

/.;  and  affection,  360,  361 
Quincke's  tubes,  160 

Race  psychology,  3 

Ranvier,  118 

Raphael,  hallucinations  in,  211  /. 

Rayleigh,  229 

Reaction,  motor,  native,  and  acquired, 
397  JF-,  410 /.;  co-ordinated  and  unco- 
ordinated, 397  Jf.;  and  attention,  75  /., 
80  Jf.;  and  meaning,  202,  204,  302,  335, 
351,  417;  in  appetition  and  aversion, 
369;  instinctive,  in  emotion,  377  Jff., 
384  JT.;  vocal  language  as,  317  jf. 

Reaction  time,  in  attention,  80;  in  associ- 
ation tests,  293 


480 


INDEX 


Reading,  nature  of  perception  in,  77 

Reasoning,  Chapter  XV,  338-355;  re- 
flective thinking  in,  342  jF.;  inductive 
and  deductive  inference  in,  345  jF.; 
formal  logic  and  inference  in,  349  /.; 
imagery  and  mental  content  in,  351  jF.; 
neural  basis  of,  354  /.' 

Recall,  factors  determining,  81,  243  /., 
285;  laws  of  association  in,  283  jF.; 
spontaneous,  243;  control  of,  244;  as- 
sociation by  contiguity  as  total  recall, 
288 /.;  association  by  similarity  as  par- 
tial recall,  288  /.;  desultory  memory, 
250;  logical  memory,  250  /.;  in  associa- 
tion tests,  290  JT.;  as  method  in  memo- 
rizing, 253;  neural  basis  of,  241  /. 

Recapitulation,  4 

Recency,  243,  282,  285 

Recognition,  feeling  of  familiarity  in,  204, 
245 /.,  247,  258;  function  of,  247 /.;  in 
perception,  200,  203 /.,  246 /.,  321,  337; 
in  memory,  241,  245  jF.,  258,  260;  as 
consciousness  of  relation,  337;  and  the 
self,  435;  in  paramnesia,  258 

Reed,  12 

Reflective  thought,  see  Reasoning 

Reflex  theory  of  instinct,  411  /.  * 

Reflexes,  397  jf.;  compensatory,  115; 
pupillary,  170 

Regression,  law  of,  256 

Relationship,  consciousness  of,  17,  299 
f->  336 /.;  implicit  .in  perception,  299  /., 
321,  337;  explicit  in  judgment,  321,  330, 
332/->  334 /•;  consciousness  of  meaning 
as,  308;  context  of  consciousness  in, 
351  /.;  affection  and,  358 

Relativity,  theory  of,  103 

Relaxation,  as  affection,  359;  cognitive 
elements  in,  360 

Religious  experience,  feelings,  373;  senti- 
ments, 376 

Repetition,  as  method  in  memorizing,  253; 
and  association,  282 

Respiratory  sensations,  no;  see  Organic 
sensations 

Retardation  of  sensation,  94;  in  pressure 
and  pain,  123;  in  cold  and  warm,  125; 
in  salt  and  bitter,  140 

Retention,  in  memory,  241,  252;  as  or- 
ganic memory,  248;  neural  basis  of, 
241,  252,  256 

Retina,  166,  i6§/.,  Fig.  54;  color  zones  of, 
1 88;  corresponding  points  on,  107, 

2I9/- 


Retroactive  inhibition,  282 

Relzius,  1 1 8,  150,  138 

Reverie,  264 

Rhythm,  organic,  sensations  of,  in  time 

perception,  233 
Ribol,  8 1 
Rivalry,  in  olfactory  sensations,   135;  in 

gustatory    sensations,    141;    binocular, 

7i /• 

Rivers  and  Head,  128 
Rods  and'  cones,   166,   168;  distribution, 

169;   differentiation   of   function,    175, 

194;  in  total  color-blindness,  190 
Rote  memory,  251 
Ruger,  405 
Rutherford,  151 

Saturation  of  colors,  181;  in  Helmholtz 
theory,  191;  in  Hering  theory,  193 

S chafer,  34,  132 

Schumann,  326 

Schwalbe,  31 

Science  and  imagination,  261  /. 

Seguin,  173 

Self,  Chapter  XX,  432-462;  nature  of, 
!?/•>  434  JF-,  442;  egoistic  reference  of, 
438;  dynamic  aspect  of,  434  /.,  439 /.; 
continuity  of,  432  /.,  443,  446;  origin 
and  growth  of,  435  /.,  438;  social  factor 
in,  436,  437,  438  /.;  contents  of,  437; 
kinjesthetic  and  organic  sensations  in, 
18,  112,  417,  435,  437;  memory  in,  437; 
attention  and,  440;  sensation  and,  439; 
perception  and,  440;  feeling  and,  441; 
interest  and,  440  /.;  suggestion  and, 
453;  will  and,  425,  427  jf.,  442;  con- 
flicts in,  428;  disturbances  of,  446;  dis- 
sociations in,  446  jf.;  dreams  and,  444 
/.;  sleep  and,  443 

Semicircular  canals,  sensations  from,  115; 
see  Kinaesthetic  sensations 

Seneca,  memory  in,  258 

Sensation,  Chapter  IV,  87-109;  as  an  ele- 
ment of  consciousness,  87,  115,  351; 
definition  of,  87,  204;  pure,  88,  204, 
300;  attributes  of,  97  JF.,  105  /.,  357  /.; 
modality  in,  98;  quality,  97  /.;  inten- 
sity, 98  jf.;  duration,  105,  230  jF.;  ex- 
tensity,  103 /.,  214  jF.;  classification  of, 
107  Jf.;  retardation,  94;  threshold,  99 
/.;  adaptation,  96;  after-image,  94  /.; 
complexes  in,  143;  local  sign  in,  io6/., 
213  jf.;  and  perception,  115,  197  Jf.,  204; 
and  imagination,  238,  262,  266  Jf.; 


INDEX 


481 


imageless  thought,  351;  and  conscious- 
ness of  relation,  351;  and  affection,  356 
/•,  359.  361  /.,  366,  367 /.;  and  the  self, 
439;  neural  basis  of,  88  jf.,  98,  104 

Sense-organs,  function  of,  88  /.;  evolu- 
tion of,  90  /.,  135,  194;  stimuli  of,  89, 
91  f.,  in,  112,  116,  124 /.,  130 /.,  138, 
152 /.,  176  /.;  range  of  response,  131, 
iS5>  177;  latent  period  of,  94,  123,  125, 
140;  inertia  in,  94/.,  99/-,  122  /.,  133, 
142,  161,  185  /.;  adaptation  in,  96  /., 
124,  127,  134,  141,  175,  180,  184  /.; 
accommodation  of,  in  attention,  54,  73 
/-,  83,  169 

Sensory  aphasia,  51,  152,  201,  447 

Sensory  areas  in  cortex,  47/.,  i2o/.,  130, 
152,  172 /.;  Figs.  28,  29,  30,  58 

Sensory  tracts,   from  skin  and  muscles, 

43,  i2o/.;  Figs.  1 8,  22;  from  olfactory 
cells,  130;  from  taste-buds,  138;    from 
vestibule,    46,      152,    Fig.     25;    from 
cochlea,  46,  152,  Fig.  24;  from  retina, 

44,  172,  Figs.  23,  54,  58 
Sentiments,  375 

Sexual  sensations,  see  Organic  sensations 

Shepard,  382 

Sherrington,  381 

Sidis,  454 

Similarity,  law  of,  in  association,  285 /.; 
in  re5<soning,  350 

Skill,  acts  of,  organic  memory  in,  248; 
motor  connections  in,  279;  method  of 
learning,  406  /. 

Sleep,  443  /. 

Smell  sensations,  see  Olfactory  sensations 

Sobotta-McMurrich,  28 

Social  factors,  in  self,  436,  437,  438  /. 

Social  experience,  373,  376 

Social  psychology,  2 

Somaesthetic  area,  i2o/.,  Fig.  28 

Somnambulism,  449  /. 

Sonometer,  157 

Soul,  i,  15 

Space  perception,  nature  of,  212  /.; 
theories  of,  2 13 /.; -synthesis  of  sensa- 
tions in,  103  /.,  106,  114  /.,  i?2,  172, 
2i3./F->  219  JF.,  225 /.;  illusions  in,  206 /., 
222  Jf.;  see  Auditory,  Visual,  and  Tac- 
tual space  perception 

Specific  energy  of  nerves,  90 

Specious  present,  232  /. 

Spectrum,  physical  nature  of,  176  /.; 
sensation  qualities  in,  179,  182;  inten- 
sity of,  and  brightness,  180;  saturation 


of  colors  in,  181;  to  light  and  dark 
adapted  eye,  i8o/.;  to  color-blind,  189, 
190 

Speech  centres,  so/.;  see  Language 

Spencer,  385,  386,  411 

Spencer-Bain  theory  of  origin  of  con- 
sciousness, 411 

Sphygmograph,  364 

Spinal  cord,  23,  30,  40  JF.,  129,  401;  Figs. 
5,  10,  18,  20,  21,  22;  see  Nervous  sys- 
tem 

Spiritualistic  hypothesis  of  consciousness, 
10  ff. 

Spontaneous  attention,  59,  85 

Starr,  46 

Static  sensations,  see  Kinxsthetic  sensa- 
tions 

Steinthal,  292 

Stereoscopic  vision,  107,  219  Jf.;  binocular 
rivalry  in,  71 

Stern,  290 

Stimuli,  of  sense-organs,  nature  of,  91  f. ; 
classification  of,  92;  adequate  and  in- 
adequate, 89,  92,  176;  intensity  of,  and 
sensation,  99  JF.,  122,  133,  142,  161,  180; 
duration  of,  and  sensation,  94  f.,  123 
f.fl2j,  134,  142,  184 /.;  classification  of 
sensations  according  to,  107 

Stout,  251,  315,  319 

Strain,  as  affection,  359;  cognitive  ele- 
ments in,  360;  see  Effort 

Strieker,  272 

Stumpf,  164 

Subconsciousness,  57,  296 

Suggestion,  in  hypnosis,  451  ff.;  in  hys- 
teria, 461;  illusions  in  memory  due  to, 
258,  289;  individual  differences  in,  452 

Sully,  206 

Summation  tone,  160 

Superstition,  342 

Syllogism,  and  reasoning,  349 

Sympathetic  nervous  system,  see  Auto- 
nomic  nervous  system 

Sympathetic-resonance  theory  of  hearing, 

i5°/-.  iSS.  162 

Synsesthesia,  2707. 

Synapse,  37 

Synthesis,  in  perception,  88,  197  f.,  321, 
325;  of  sensations  in  space  perception, 
172,  213  ff.;  of  sensations  in  time  per- 
ception, 231  Jf.;  in  judgment,  333 /. 

Tachistoscope,  76,  200 

Tactile  sense,  see  Cutaneous  sensations. 


482 


INDEX 


Tactual  space  perception,  extensity,  103 
/.;  local  sign,  106,  122,  214;  synthesis 
with  kinaesthetic  and  visual  sensations, 
2I3  Jff-'t  illusions  in,  206 /.,  222 /. 

Taste  sensations,  see  Gustatory  sensations 

Taylor,  315 

Telephone  theory  of  hearing,  151 

Temperament,  373 

Temperature  sensations,  see  Cutaneous 
sensations 

Tendinous  sensations,  see  Kinaesthetic 
sensations 

Tension,  as  affection,  359 

Testimony,  246,  258  /.,  289 

Thermal  stimuli,  92,  i24/. 

Third  dimension,  perception  of,  218  Jf. 

Thirst,  92,  109,  no 

Thorndike,  33,  113,  119,  170,  249,  389,  405 

Threshold  of  sensation,  99  /. ;  of  pressure 
sensations,  122,  215,  217;  of  olfactory 
sensations,  133;  of  gustatory  sensa- 
tions, 142;  of  auditory  sensations,  161 

Timbre,  158,  229 

Time  perception,  230  /.;  sensory  material 
in,  105,  231  Jf.,  235 /.;  duration  and  suc- 
cession in,  231  /.;  psychical  present  in, 
232  Jf.;  measure  of,  234  Jf. 

Tilchener,  56,  105,  108,  in,  115,  117,  118, 
155,  182,  351,  353,  359,  360,  367,  411 

Tone,  109,  144,  issjf.;  see  Auditory  sensa- 
tions 

Tone-deafness,  157 

Total  recall,  250,  288  /. 

Transfer  of  training,  252 

Trial-and-error  method,  297,  405  Jf. 

Unpleasantness,  and  pain-sensation,  124, 
362;  see  Affection 

Value,  judgment  of,  328 

Van  Gehuchten,  29 

Vestibule,  sensations  from,  115;  distribu- 
tion of  fibres  from,  45,  152,  Fig.  25;  see 
Kinaesthetic  sensations 

Vittiger,  23 

Visual  area,  44,  48,  i72/.,  Fig.  29 

Visual  purple,  174,  181 

Visual  sensations,  classification  of,  109, 
178 /.;  stimulus  of,  176 /.;  sense-organ, 


91,  166  Jf.;  brain  areas,  44,  48,  172  Jf.; 
intensity  in,  101,  180;  extensity,  215, 
218;  contrast,  i86/.;  adaptation,  96  /., 
175,  180 /.,  184 /.;  after-images,  94 /., 
185  /.;  theories  of,  190  Jf.;  imagery  of, 
267 

Visual  space  perception,  extensity,  103  /., 
215;  local  sign  in,  107,  214 /.;  eye  move- 
ments in,  115,  214,  217  Jf.,  221,  225/.; 
synthesis  of  cutaneous  and  visual  sen- 
sations in,  172,  213  Jf.;  binocular  vision 
in,  107,  219  Jf.;  association  aids  in,  221 
/.;  development  of  projection  in,  2i6/.; 
illusions  in,  222  Jf. 

Vividness,  as  attribute  of  sensation,  105; 
factor  in  association,  243,  285 

Vocal  sound,  in  language,  317,  319 

Volitional  action,  401  Jf.,  420  Jf. 

Voluntary  attention,  60.  85 

Wandering  attention,  67 

Ward,  411 

Washburn,  351 

Weber's  law,  101  /. 

Wernicke's  centre,  51 

Whipple,  289,  291 

Will,  Chapter  XIX,  410-431;  nature  of, 

421  /.;  theories  of,  420  /.;  content  of 

consciousness  in,  402 /.,  420  Jf.,  425 /.; 

and  the  self,  427  Jf.,  442;  freedom  of, 

429 /. 

Wilson,  229 
Wolff,  358 
Wood-worth,  352 
Word-blindness,  51,  201 
Word-deafness,  51,  152,  201,  447 
Word-image,  27 1 /.,  305,  320 
Writing,  imitative  tendency  in,  315 
Wundt,  214,  359,  386,  389,  395,  411 

Young-Helmholtz  theory  of  color  vision, 
191 /• 

Zeno,  391 

Ziehen,  103,  366 

Zola,  olfactory  imagery  in,  268 

Zollner  figure,  224 

Zwaardemaker,  132 


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